On my second day in Budapest last July I learned that a district downtown here was evacuated the previous day because of a WWII bomb. The live 500-kilogram bomb was discovered during an excavation. The next day I read about another one having been discovered elsewhere in Hungary. Since then other stories about other bombs found during construction have continued to pop up. From my count there have been five more stories since July, including the one in yesterday's news, about an area around the Margaret Bridge being evacuated while a bomb was lifted from the Danube. Often story includes some version of an account from a neighbor having lived above a buried bomb for years without realizing it.
It makes me curious about how common this sort of thing is elsewhere in Europe...