Here is a very rough summary of what I was thinking....
First I want to discuss the implied location and setting of Eden in biblical sources, which are not uniform, but which suggest a mythological locale near or on a sacred mountain where the creator god El (in the OT, El was named as the god of the patriarchs) lives, which was the source of the waters of the world and where a grove of trees was located. This was an abode of the gods, "the divine council" or "divine assembly" convened with El (also called the seventy sons of El and his consort Asherah), much like the Olympian gods atop Mount Olympus. For the Canaanites, who were the ancestors of the Hebrews at least in part, this was mostly localized in Lebanon, and we also find this same region associated closely with Yahweh outside of the Eden narrative (see Psalm 29 and 42). Ezekiel 28 and 31 locate the garden of Eden on a mountain ("the holy mountain of assembly") and it is in Lebanon, as it includes cedars that are the "choicest of Lebanon". Some placed the divine abode on Mount Hermon in the Anti-Lebanon range, which was the source of the Jordan; others placed it on Mount Lebanon (at the peak Afqa). In between the two ranges is a very fertile plain (the Beqa'a Valley) with springs that was the source of the two major rivers of Lebanon: the Orontes River and the Litani River; Mount Lebanon itself at Afqa was the source of the Nahr Ibrahim, or Adonis, River, and a fourth river flowed out on the other side of the mountain. The valley nearby may have been the location of the gardens for the Mount Lebanon divine abode (the major cultic center Baalbeq, where El, Baal, and later Baachus were worshipped, was located just across from Afqa at the spot between the two rivers), as Ugaritic texts state that El resided in a tent at a mountain at the source of the two rivers (curiously enough, Paradeisos was the name of a town on the Orontes River at the north end of the Beqa'a Valley, and Amos 1:5 refers to a Beth-Eden in poetic parallelism with the "Valley of Aven," i.e. the Beqa'a Valley; although Beth-Eden is usually identified with Bit-Adani on the Euphrates the connection with the Valley of Aven might suggest an identification with Baalbeq).
The Eden narrative in Genesis 2-3 instead points to a localization in northern Mesopotamia in the Urartu region, at the source of the Euphrates and Tigris Rivers, which is the same localization in the Hittite/Hurrian myth of Elkunirsha (essentially locating the divine abode in the Hurrian homeland); this suggests perhaps a greater Hurrian influence on the Eden narrative than could otherwise be appreciated; the Flood story similarly locates Noah's ark at "the mountains of Ararat" (= Urartu), and the Abraham narratives center on Harran as Abraham's homeland, and Abraham's ancestors Peleg, Nahor, and Serug correspond to the names of cities in the old Hurrian Mittani kingdom. Mesopotamian myth also has a range of locales; the Gilgamesh Epic draws on West Semitic ideas and places such a divine abode in the far west in Lebanon (the Cedar Mountain and the Cedar Forest, where the Annunaki and Ishtar lived), while it also put paradise at the edge of the world in the east on an island where the plant of life was located (the two locations connected via an underground tunnel through which the sun passed at night in order to rise in the East). This combines the Canaanite mythology of the Lebanon region with the native Sumerian belief about Dilmun. The Gilgamesh myth was well-known in the land of Canaan (archaeologists discovered copies of the Epic at Megiddo and at Ugarit) and unmistakably was the source of many Jewish themes and motifs (particularly found in the Enochic literature). There were also Greek myths closely connected with these (since the Hittites and Phoenicians influenced Greek thought and since Mycenaean Greeks were living in the land of Canaan alongside the Israelites as the Philistines and possibly even the tribe of Dan), especially the myth about the Hersperides, a garden at the western edge of the world, where Heracles battled a dragon named Ladon (= Ugaritic Lotan, biblical Hebrew Leviathan) who guarded the golden apples. This conflict may have been a reflection of the Mesopotamian myth of Gilgamesh battling the monster Humbaba in the abode of the gods at the Cedar Forest in the Lebanon mountains, and the later Canaanite myth of Baal/Zeus battling the dragon Yamm/Typhon from Mount Lebanon downstream to Mount Casius (creating the Orontes River, which in ancient times was called the Typhon or Draco River), and of course of Yahweh battling Leviathan/Rahab/Yam. Defeating Ladon allowed Heracles to steal the forbidden golden apples (cf. the jeweled fruit in the Gilgamesh Epic, and the jewels in Eden described by the prophet Ezekiel).
Since the garden was conceptualized as the abode of the creator god ('il qn 'rts "El creator of the earth" was a common epithet of El, found in expanded form in Genesis 14 as the god worshipped by Melchizedek and from which the Hittite/Hurrian god Elkunirsha derives his name), ususally on a mountain at the source of the subterreanean deep, temples were construed as representations of this divine abode (often containing a central tree of life). The Judaeans localized Eden at Mount Zion (note that Yahweh had a variety of mountain abodes, e.g. Mount Sinai and Horeb, Mount Gerizim, Mount Hermon), which in Jewish tradition was located over the watery deep and where there was a spring named Gihon (one of the rivers in the Eden narrative), and the First Temple was built by Phoenicians who brought timber from Lebanon to construct the temple — a link to the notion of Eden being in Lebanon. The interior decorations of pomegranates and lillies gave the temple a garden-like setting and the menorahs represented trees. At one time the temple also contained an image of Asherah (who was usually depicted in aboreal imagery as a tree or pole), the consort of El in Canaanite religion and of Yahweh in henotheistic Yahwism. Asherah was a goddess of life and healing, and was conceptualized as the tree of life; thus the image of the Asherah in the Temple may have depicted the central tree of life in the garden. There was also the Nehushtan serpent idol that the Israelites worshipped (which was also a source of healing from snakebite) and it is likely that this was located in the Temple as well with the Asherah (the story of the Nehushtan pictures it as placed on a pole). Another feature of the Asherah cult had to do with clothing. The modern practice descended from ancient Asherah worship is that the clothes of sick people are placed on sacred trees in order to transfer the curative powers of the tree onto the clothes (the fruit of such trees incidentally is strictly forbidden). At the Jerusalem Temple, there was a minor industry of women weaving clothes for Asherah. So the cultic practice of placing clothes on the naked idol has resonance with the Eden narrative, in which the primal woman is naked, becomes clothed, and is associated with a tree with forbidden fruit and a snake. There are further links to Asherah. She was the mother of the gods and known as the "mother of all," the same epithet applied to Eve in the Eden narrative. Also the primal woman is named Chawwah "Eve", an epithet identical to a name for Asherah/Elat used by the Phoenicians -- Chawat. This name also may have arisen from the name of the Hurrian goddess Hebat, who was worshipped in Jerusalem by the Caananites (cf. the name of Jerusalem's king Abdi-Heba "Servant of Hebat" in the Tel el-Amarna letters). There is further evidence of Asherah/Elat (Elat meant "Goddess", as Asherah was the goddess par excellance) in Egypt and Sinai that is of pertinence. In Egypt, Asherah was worshipped with the name Qudshu (from a Canaanite word meaning "holiness") and she was regularly depicted in art with serpents. Syncretized to Hathor, the patron goddess of mining, Canaanite slaves working in the mines of Sinai built several temples dedicated to Hathor/Elat. These temples refer to Hathor/Elat as "Serpent Lady" and one of these temples contained a bronze serpent, exactly akin to the Nehushtan which the Bible describes as fashioned by the Israelites in the wildness of Sinai to protect them from snakebite. This further supports the linkage between Asherah and the serpent. There was also another Canaanite myth of pertinence here: when the daughter of the sun goddess Shaph was bitten by a snake, the chthonic god Horon went to a well-watered grove far in the east along the Tigris River (which is associated with the location of Eden in Genesis 2), and obtained fruit and cuttings from the "tree of death" which he then used to heal the snakebite and bind the serpent. So the Jerusalem Temple had many features of the paradise myth: It was located on the mountain where Yahweh was believed to dwell atop subterannean waters, it was constructed of wood from Lebanon by a Phoenician king, it was decorated as a garden inside and had an Asherah image likely depicting the "tree of life", an image that would be clothed by Aserash's devotees, and also probably the Nehushtan, a serpent idol. Finally, there were cherubim at the east entrance of the tabernacle and the Temple guarding the entrance. Then in the reforms of Hezekiah and Josiah, the Asherah image and the Nehushtan were both expelled from their place of veneration and were then destroyed, paralleling the expulsion of Eve from the garden.
The other features of the Eden narrative concern the eating of fruit that brings death, the refusal of the fruit of life, the giving of wisdom to mankind, the introductioin of evil and death into the world, and the fall of man from divine favor, or instead, independence from primal servitude. These have strong parallels with Mesopotamian, Canaanite, and Greek myths. The biblical Eden narrative has a parallel in Ezekiel where Eden was localized in Lebanon and in which a divine figure (one of the cherubim) fell from divine favor because of pride and fell down to Sheol. This is parallel to the myth about the morning star in Isaiah 14 (which gave rise to the Christian Lucifer legend), who similarly experiences a fall due to pride. One might recall a similar theme in the Eden narrative: the primal humans have access to immortality with the tree of life but are denied divine wisdom, attaining such knowledge would "make you like the gods", and so they reach for that higher status, and then are expelled from the divine presence. What is interesting about the morning star myth is that there is a clear parallel in the Ugaritic Baal myth: When Baal dies and is taken into the underworld, Athtar (= the morning star) the consort of Athtart (= the evening star), who was equivalent to Ishtar of the Babylonians, Inanna of the Sumerians, and Aphrodite of the Greeks, decided to take over Baal's throne at Mount Saphon. But when Baal was rescued from the underworld, he kicked Athtar off his throne and put him down low (explaining why the planet Venus never rose high in the sky), taking Athtar's wife Athtart as his own. Now there was a separate legend about Inanna/Ishtar and Dumuzi/Tammuz, with the latter dying and going to the underworld, whose demise was ritually mourned, even in Jerusalem. All of this has a close connection with the region in Lebanon associated with the divine abode. In the Gilgamesh Epic, the Cedar Mountain was ruled by Ishtar and Gilgamesh had to defeat and slaughter her guardian of the forest Humbaba. Mount Lebanon in the later period was also still associated with Ishtar/Astarte/Aphrodite, with many temples dedicated to her there, and the peak Afqa at Mount Lebanon was the site where Adonis (= syncretized to Tammuz and Baal) was killed and his blood ran into the river (explaining the reddish color of the Adonis River). Anyway, so this was the location where figures associated with Ishtar/Aphrodite were killed, and the story in Ezekiel of the divine cherub demoted in an act of pride is parallel to the story in Isaiah 14 about the morning star, and in the Baal Cycle the morning star (Athtar) was demoted after taking Mount Saphon for himself. Each of these are different independent stories, but there are common threads shared by them that show they draw on related traditions.
There are even closer ties to certain Mesopotamian myths. As mentioned above, the Gilgamesh Epic places the divine garden at the eastern edge of the world at Dilmun, where the plant of life was found. But before Gilgamesh achieved immortality, a snake came and stole the plant and itself became immortal, shedding its skin. Another myth concerned the first mortal, named Adapa. He was part-divine himself, being the son of Ea, the god of wisdom. It should be noticed that Ea entered into the Hurrian/Hittite pantheon, which was then adopted by the Canaanites, and there Ea was identified with El, the creator god. This would make Adapa correspond to the first mortal son of El. Ea was the god of the sweet water and was closely associated with the subterranean deep, a feature of ANE notions of paradise. Adapa brought the arts of civilization from the paradise of Dilmun and built the first city Eridu (compare the biblical story of Cain building the first city and naming it after his son 'Irad, which is similar to Eridu), and taught the secrets of civilization to the human mortals living there (making him the first apkallu, or "sage", cf. the narrative of the descendents of Cain discovering the arts of civilization). Now Adapa was not fully divine; he had divine wisdom on account of being the son of Ea, but he did not have immortality. And at the time there was a conflict between the gods Ea and Anu, the god of Heaven. This conflict runs through the mythologies from the Hurrians to the Phoenicians all the way to the Greeks. In Hurrian-Hittite myth, Anu, the god of Heaven, was eventually defeated by Ea, being castrated by him. The castration was a creative act: this is what separated Heaven and Earth from each other (cf. Genesis 1:6-8). Philo of Byblos related the Phoenician myth that Uranus ("Heaven" = Anu) was castrated by Kronos (= El, who was equivalent to Ea) at the same location where Adonis was killed in the Aphrodite-Adonis myth, with the red color of the Adonis River (modern Nahr Ibrahim in Lebanon) resulting from the blood of Uranus pouring into the river. And Hesiod similarly related the Greek myth about Kronos castrating Uranus, and it was from his severed genitals that Aphrodite was born. Interestingly this might link back to the Eden narrative, since Eve was created from a bone taken from Adam's body, and some philologists have independently suggested that the word translated "rib" was the baculum of the penis (the myth etiologically explaining why humans males do not have a bone in their genitals). Hesiod claimed that the father of Adonis was Phoenix, the eponymous ancestor of the Phoenicians. So we clearly here have a Phoenician myth about the birth of Aphrodite (=Astarte/Ishtar) and Adonis in the paradisical land around Mount Lebanon. And this was the same place that, according to the Gilgamesh Epic, was the abode of the Annunaki gods and according to the Enuma Elish and the Atrahasis Epic, humans were created by the Annunaki as their workers (cf. Adam being created "in the garden of Eden to tend and keep it", Genesis 2:14). The Annunaki are parallel to the Titans of Greek mythology, those gods associated with Kronos (= El) who would later be defeated by Zeus (= Baal) in the war against the Titans, with the Titans becoming imprisoned under the earth at Tartarus — a clear parallel to the myths of the morning star and the Eden cherub in Isaiah 14 and Ezekiel 28, who fall from grace and fall to Sheol. But anyway we need to leave Lebanon and return back to the original Sumerian myth of Adapa, which concerned the island paradise of Dilmun in the east and the first city Eridu, where Adapa brought the arts of civilization. During this conflict between Anu (= Uranus) and Ea (= El), Adapa came before Anu and Anu offerred him, as a reward, the food of life that would bestow on him immortality and make him equal to the gods. This is the equivalent to the serpent offering Adam the food of divine wisdom, which would make Adam equal to the gods (Genesis 3:5). Ea however warned Adapa that this was a lie. According to him, the food of life was actually the food of death (cf the "tree of death" in the Canaanite snakebite myth about the grove of trees alongside the Tigris), and that if Adapa would eat the food, he would die. This is parallel to God's warning to Adam and Eve about eating from the tree of knowledge of good and evil (divine wisdom), and also shares the same theme of lying. Adapa took his father at his word and refused the offer of the food of life, thereby missing out on the opportunity to immortality. Similarly, Adam and Eve on account of their actions miss out on eternal life as well, with the tree of life now out of reach.
There were also two Greek myths closely connected together that are closely paralel to both the story of Adapa and the Eden narrative: the myth of Prometheus and the myth of Pandora. Prometheus was the son of a Titan and a trickster adversary of Zeus (= Baal). We have earlier seen the example of Athtar as an adversary of Zeus/Baal who acts out of hubris to challenge his royal authority, but who is then humiliated and imprisoned by Zeus/Baal. Prometheus is a similar figure who challenged Zeus' omnipotence and omniscience. Now after Uranus was castrated and defeated by Kronos, Kronos ruled in his stead and created the first race of humans who were born not through sexual intercourse, as there were no women yet, but born directly from the ground from the dust. Men lived with the gods peacefully, the earth gave its fruit unbounded to men, and there was everlasting springtime. This was the Golden Age of Hesiod, which corresponds quite well to the biblical notion of Adam living with Yahweh peacefully in Eden without a female mate; Kronos however destroyed all his offspring and Uranus and Gaia (Heaven and Earth) had prophesied that Kronos would be defeated and replaced by his own son. So Gaia conspired to save Kronos' son Zeus and had him equipped with weapons with which he would defeat and replace Kronos as divine ruler. This war ended the Golden Age, and so when Zeus was enthroned: the gods shun mankind, they hide the fruits of the earth from them, forcing man to work in the field to obtain his food, and changed the nature of the animals making some venomous like serpents and others dangerous like lions and wolves. This corresponds quite well with the curses that Adam and Eve face when they are expelled from the divine presence in Eden: Adam has to till the soil and no longer has access to the fruit of the garden. The new relationship between the gods and mankind was established in a covenant declared at Mecone, which would be the first time humans would sacrifice to the gods. Prometheus however switches sacrifices and tricks Zeus into accepting an inedible sacrifice (bones wrapped with fat), a theme reminiscent of the Adapa legend in which Adapa was warned that the offer of the food of life was actually the inedible food of death. In retaliation, Zeus hides fire from mankind, just as he hid the fruits of the earth; this is parallel to Yahweh forbidding Adam from eating of the fruit of the tree of knowledge of good and evil and later of the tree of life. Prometheus however stole the fire in a fennel stalk from Apollo's sun chariot and gave it back to mankind. In some versions of the myth, Prometheus was actually the creator of the race of humans in the Silver Age, and the version of the myth in Aeschylus claimed that Prometheus did not only give fire but taught the arts of civilization to the humans. This makes Prometheus (whose name means "Forethought") parallel to the role of Adapa, as the first apkallu sage for humanity, and also to the serpent in the Eden narrative, who induces the primal man to attain hidden knowledge and attain the fruit that Yahweh had forbidden to him. But to punish mankind, Zeus had the craftsman god Hephaestus (= the Canaanite god Kothar) fashion the first woman from the clay of the earth, named Pandora ("All Giving", but possibly connected to the Canaanite goddess Pidray, daughter of Baal), who went to live among mankind and Prometheus' brother Epimetheus. Pandora carried with her a jar containing her gifts from Zeus. Prometheus warned Epimetheus to not accept any gift from Zeus, as it would be a trick (cf. Ea warning Adapa against accepting the food of life from Anu). But the jar was opened and mankind became afflicted with the curses contained therein, including sickness, pain, toil, and death. In the Eden narrative, Adam is warned by Yahweh not to eat the fruit of the tree of knowledge of good and evil, and the eating of the fruit is parallel to the opening of Pandora's jar. And Pandora also marked the introduction of sexual reproduction to mankind in a manner reminiscent to Eve. Just as Eve was portrayed as the vector through which sin and death came into the world in later Jewish tradition, the Greeks similarly looked to Pandora as the source of sickness, pain, and death in the world. Then Zeus had Prometheus bound and imprisoned in the Caucasus where he would be daily tortured for his deed.
Finally, it is worth considering the material in later Jewish literature, particularly the Enochic corpus (such as the Book of Watchers and the Book of Giants, both from third century BC), which incorporate mythological material deriving from local Canaanite tradition and the Gilgamesh Epic. There is no Eden narrative in this material as the source of evil in the world; instead evil is the result of the fallen angels who descend on Mount Hermon and who intermarry with human women, producing a race of giants. The fallen angels, particuarly the angel Asael, teach humankind the arts of civilization, including medicine, cosmetics, and metal working. Then God sends the archangels to seize and bind the angels and imprison them below the earth. The parallels with the other myths outlined are here clear. Adapa and other apkallu were teachers of civilization, just as Prometheus was, and Prometheus was later seized and imprisoned for doing such a thing. Also Cronus (= El) had imprisoned the Cyclopes and the Hecatonchires giants in the underworld Tartarus prison, and Zeus after defeating most of the Titans imprisoned them below the earth in Tartarus. The mythological parallel is explicit in 1 Enoch 20:2 and 2 Peter 2:4, where Tartarus is named as the place where the fallen angels were imprisoned. The giant offspring of the fallen angels (the Nephilim) were part-human and part-divine, and such is the parentage of the demigods of Greek mythology, such as Heracles. Gilgamesh was part-man and part-god in the Gilgamesh Epic, and interestingly one of the giants in the Book of Giants (among the Dead Sea Scrolls) was named Gilgamesh (another giant named in the book, Atambish, might derive from Ut-Napishtim, the Flood hero of the Epic, and a third giant was Hobabis, possibly representing Humbaba). Now the descent of the fallen angels on Mount Hermon may preserve the belief that the divine assembly of the gods was located on Mount Hermon (where El had his abode for those living in Bashan). And it was in Bashan where there was a strong tradition about giants living in the area, such as King Og in Deuteronomy, presented as one of the last of the Rephaim. Genesis 14 refers to Rephaim living in the area, and the land of Bashan is dotted with megalithic structures which probably gave rise to the idea that giants used to live there. What is interesting is that the Rephaim are usually named in the OT as the denizens of Sheol; they are chthonic figures. Gilgamesh too was a chthonic figure, as the Death of Gilgamesh poem shows. So we can kind of see how the narrative in 1 Enoch is derived from older Canaanite mythology. The gods of Hermon were the gods associated with El and they spawned the Rephaim demigod giants, who built the massive megaliths in the Bashan area, and who came to be imprisoned in Sheol; the demigod Gilgamesh, now a chthonic figure in the underworld, was one of their number (remembered by the Jews of the later period as a giant who lived before the Flood). The Book of Watchers also claims that the Watchers were imprisoned under the earth near the spring of Beth-Mayim ("House of Water," or Abel-Main in Aramaic). According to rabbinical tradition, the springs at the foot of Mount Hermon drew their water from the subterreanean deep (cf. Psalm 29, which states that Yahweh is enthroned over the flood in Sirion, and cf. the Testament of Levi in which Levi has a vision of the throne of God at "the mountain of Abilene"), including the spring of Abilene and the one issuing from the cave of Banias at Mount Hermon which produces the Jordan River. And so the fallen angels are imprisoned under the earth at "the waters of Dan in the land of Dan" where the angels are "weeping at Abel-Main which is between Lebanon and Senir" (1 Enoch 13:9-10). According to a later addition, the weeping of the angels burning in their subterreanen prison produced hot springs (1 Enoch 67:4-13), and similarly Origen wrotes that it is from the angels "buried in the earth where the warm springs come from, which are their tears" (Contra Celsum 5:52-55). So the notion of the fallen angels imprisoned under the earth is another myth aimed at explaining another geographic feature of the landscape (with the hot springs of the area representing the tears of the angels buried underground, which may derive from an older idea of the former divine assembly of Mount Hermon being imprisoned underneath the foot of the mountain. Finally, Enoch undergoes a journey to the ends of the earth very reminiscent to that of Gilgamesh in the Gilgamesh Epic. He travelled "to the west of the ends of the earth" to the fire that blazes the sun on fire when it sets on the west (1 Enoch 23), and then journeying eastward he came to "seven glorious mountains, all differing each from the other, whose precious stones were beautiful and glorious" (24:2); these mountains of precious stones are reminiscent of the precious stones in Ezekiel 28 on the mountain of God at Eden, and the jewel-laden trees in the Gilgamesh Epic. The cluster of seven mountains may reflect the range of mountains in Lebanon; these mountains had deep ravines and rugged peaks, "and the seventh mountain was in the midst of these, it rose above them in height, like the seat of a throne" (1 Enoch 24:3). This tallest mountain was the mountain of God, encircled by fragrant trees and a tree with the sweetest fragrance and leaves and blossoms that never wither, identified by Michael the archangel as the tree of life (ch. 25). The Enochic corpus thus appears to attest a similar concept of Eden found in Ezekiel.
Anyway, we do not have in Genesis or in any of the other biblical and Jewish works a direct reproduction of older Canaanite and Mesopotamian myths, but there is a clear connection. Mythological ideas crossfertilize and mix and match with other existing cults with resultant syncretism, and mythologies are differently localized from place to place. But we can find that the biblical material is part of this complex interlayered stream of primeval myths concerning the abode of the gods and the origin of humankind. Anyway, there are some of the things that come to mind, in many ways this presentation has barely scratched the surface.
