Link: https://www.nationalgeographic.com/travel/destinations/asia/cambodia/what-to-do-in-siem-reap-eco-sustainable-tourism/?cmpid=org=ngp::mc=social::src=facebook::cmp=editorial::add=fb20181130travel-beyondangkorwat::rid=&sf203240346=1
Quote: "Angkor Wat, the world’s largest religious monument and a UNESCO World Heritage site, is a must-see for many travelers. This iconic temple complex in the Siem Reap province of Cambodia attracts nearly 2.5 million foreign visitors annually—a number that is growing by about 15 percent each year. Yet the province remains one of the poorest in the country."
There's a good video in the above link, but if cant access it, try this NG video from youtube.