Bannerman Castle, Pollepel Island.

The tl;dr version of the story is that the castle was built as a giant warehouse for shameless businessman and arms dealer Frank Bannerman (think a sort of Reconstruction-era Tony Stark, minus the armor) who, upon seeing some castles while vacationing in Scotland, sent home some pencil drawings he had made to his people and told them to get building. The warehouse was full of guns, ammunition, bombs and powder, and one day in 1920 (two years after Mr. Bannerman's death) there was an unknown accident and the place went ka-boom. According to some accounts, the explosion could be heard up to 70 miles away (one can only imagine how loud it would have been for Mrs. Bannerman, who was at the island residence at the time, just a few hundred yards away). Disaster no. 2 occurred in 1969 in the form of an enormous fire that destroyed the remaining roof and interior of the castle. Disaster no. 3 occurred just a few years ago, in winter of 2008, when accumulating ice and snow collapsed about half of the exterior wall. We were lucky to be able to stop by for a close look before it was too late.