Unfinished/abandoned hotel “Republic” in the centre of Kaunas, Lithuania. (Construction began in 1985)
This current wreck of an unfinished building is looked upon as the most noticeable paradox in the history of Lithuanian architecture and urban planning; a massive investment into tourism infrastructure was to be one of the biggest projects during the Soviet period of the area. Even, though, nowadays it is regarded a massive scar in the urban outlook of the city and a reminder of times passed.
Sources/more info (in Lithuanian): http://www.autc.lt/Public/HeritageObject.aspx?rt=3&type=2&ss=respublika&id=585