Christiansted National Historic Site preserves the most intact collection of 18th-century Danish colonial architecture in the Caribbean. The site encompasses Fort Christiansvaern, the Scale House (the old customs building), the Danish West India and Guinea Company Warehouse, the Steeple Building (the island's first Danish Lutheran church), and the old Public Market. Together they form a tight cluster along the harbor that gives a remarkably complete picture of what a prosperous Danish colonial port looked like in 1750.
The fort is the dominant structure — a bright yellow four-bastioned fortress completed in 1749, whose cannons were never fired in anger. Walk the ramparts for views over the harbor and Protestant Cay, and through the rooms to see the dungeon, the guard quarters, and the officers' mess. The Scale House next door functioned as the customs weighhouse; its courtyard now has information panels on the history of the slave trade on St. Croix. The National Park Service manages the site with honest attention to the full history, including the Danish colonial economy's absolute dependency on enslaved labor.