St. Thomas's oldest standing structure, this remarkable building was built between 1672 and 1680 and now has U.S. National Landmark status. Over the years, it was used as a jail, governor's residence, town hall, courthouse, and church. In 2005, a multimillion-dollar renovation project started to stabilize the structure and halt centuries of deterioration. The fort re-opened for public tours in 2014. Inside you can visit the inner courtyard and rooms, and from the outside, you can see the four renovated faces of the famous 19th-century clock tower.