A recent BBC feature has some fascinating images of forgotten (nearly) structures built during the glory (sort of) days of the Soviet Union.
On those pages you can see the world's largest diesel powered submarine and a strange looking amphibian built for anti-submarine warfare.
http://www.bbc.com/culture/story/20150819-restricted-areas-eerie-relics-of-a-forgotten-russia
and
http://www.businessinsider.com.au/soviet-unions-bartini-beriev-vva-14-plane-2015-1