Known as Bannerman Island, this tiny Hudson River outcrop comes with a wonderfully curious past. In the early 1900s, arms dealer Francis Bannerman built a castle-like arsenal here to store his vast collection of military surplus, creating a Scottish-inspired folly against the rugged Hudson Highlands. Today, its weathered towers and crumbling walls rise above the water like the set of a gothic film. Boat tours from Beacon offer a closer look at the ruins and the island’s overgrown gardens.



