The town of Philipsburg boasts the remains of two historic forts that bear witness to its strategic importance in days of old. Fort Amsterdam, the first Dutch military establishment in the Caribbean, was built in 1631 on a peninsula between Great Bay and Little Bay, but it was captured almost immediately by the Spanish. The Spanish later abandoned it, and the little fort returned to Dutch hands, being kept in use right up to the 1950s as a signalling and communications station. Interestingly, Fort Amsterdam has become an important breeding site for brown pelicans.
The other fortification, Fort Willem, lies to the west of downtown Philipsburg, topped with a television transmission tower. Both forts are worth the walk to visit, particularly for the panoramic views afforded from their elevated positions.