If you’ve ever been hiking in the Hudson Highlands or taken a train along the Harlem River anywhere north of Beacon, you’ve probably noticed the old castle on Pollepel Island in the middle of the Hudson. Like me, you probably assumed it was the leftovers of a grand estate or some sort of military base. The “castle” is actually a warehouse that was built by Francis Bannerman, a guy that owned a military surplus company as a place to store all of the stuff he’d buy at auction to sell later.
Bannerman grew up in Brooklyn and took over his father’s Navy store during the Civil War. When the war was over, young Bannerman started buying up goods from the military in order to sell for profit at his store on 501 Broadway in Brooklyn. As his inventory grew, he ran out of space in the city and decided it would be safer to keep all of the explosives in a less populated area. He then bought Pollepel Island in 1900 and began construction, which lasted until he died in 1918. Bannerman apparently designed all the buildings on the island himself, including the castle warehouse, which essentially acted as a giant billboard for his business. Two years after his death, a huge explosion destroyed the warehouse. Totally unrelated, the government started regulating the sale of weapons, which hurt the business that his family had tried to keep going.
New York State bought the island in 1968 and is officially part of the Hudson Highlands State Park Preserve and is on the National Register of Historic Places. Another fire in 1969 resulted in even more damage, so the parks department opted not to open the island to the public for a few decades.
More recently, a volunteer group has started offering tours of the island, which is how I ended up visiting. For $35+, you are brought to the island on a boat from Beacon or Newburgh and then given a few hours on the island. You’re basically stuck on a tour the whole time and most of the island is technically off limits. When you see some of these buildings up close, it makes sense that you can’t go near them because it looks like they’re about one storm away from falling over. In fact, some of the castle warehouse did fall down back in 2010.
The tour guides I interacted with weren’t exactly history nerds, and most of the information we were given was more based on myths and gossip rather than anything fact-based. Personally, this drove me crazy, but it’s the only way to get onto the island without kayaking over from the mainland (and I can’t swim).