Dating from the 17th century, this much-modified fort is now home to government offices. Inside the large courtyard (enter through the gate on the western side), mustard-yellow Dutch colonial architecture is on full display. The only building that's open to the public is the 1769 Fortkirche, which is the oldest church on the island. It contains the original pulpit and governor's pew, with other historic items on display in the small museum.