This is the Ruinenvilla in Dehnepark, in Vienna. It was a mansion built in the shape of a ruin during the 19th century.
The Austrian actor and movie director Willi Forst bought this house at the end of his career around 1960. He lived there until the death of his wife in 1973.
This old stone building is falling apart and the city will eventually tear it down as it's not practial to maintain it.