Fort Amsterdam

Set on the promontory that separates Great Bay and Little Bay, this Dutch military base was Holland's first island outpost. Built in 1631, the fort was intended to solidify a claim for control of the island's salt resources. It was later co-opted by the Spanish and then picked up by the Dutch again after the Spanish abandoned the island. The hike up to the fort isn't too strenuous, and the views it affords are absolutely worth the effort.