The Danes built Fort Christiansvaern from 1738 through 1749. Their goal was to protect the harbor and their fledgling settlement against potential attacks from the British, French, privateers and slaves. The cannons never fired a shot in battle. Fort Christiansvaern (Christian’s Defense) remains unchanged from colonial times except for an expansion from 1835 to 1841. After 1878, the fort was repurposed several times as a courthouse, prison and police headquarters. Today, it is a popular tourist attraction.