This is a view not many in Prague know. That green building is a water power plant at Stvanice island. And it is unknown for a reason. The road along the river is under ground here (so you can't see it from car) and it is kinda isolated from the tourist center of Prague by lots of old but not that special buildings - although it is very close, about 5 mins from Florenc metro station and 10 from Prague's Old Town. Mostly locals go and sit on the bench here. And skateboarders, because there's a skate park at Stvanice island :)
Place from which the photo was taken: Bank with a Prague castle view and a skatepark nearby