The sign on the castle’s side (‘Bannerman’s Island Arsenal’) offers more than a hint at this sprawling ruin’s frankly bizarre backstory. The Bannerman Castle complex, around 50 miles north of New York, on Pollepel Island on the Hudson River, was initially built as a storage site for munitions merchant Francis Bannerman in 1900. A year later, the Bannerman family added the crowning Scottish estate-style castle. In 1920, some 200 pounds of shells exploded, destroying a huge section of the complex, while a fire in the ’60s also contributed to the ruin. Tour groups are now a regular sight here, and for good reason.
Know before you go: The Bannerman Castle Trust hosts excellent weekend tours, which include a scenic boat ride followed by a walking tour of the island.