Built in 1631 on the peninsula between Great and Little bays as the Caribbean's first Dutch bastion, Fort Amsterdam was promptly captured by the Spaniards, who made it their most important garrison outside El Morro in San Juan before abandoning it in 1648. Only one small intact storage building, a few walls, and rusted cannons remain, but it's most noteworthy for its smashing views of Philipsburg. Easiest access is via the Divi Little Bay Beach Resort (guards will let you pass if you tell them you're hiking to the fort).