Charleston.

Enter a colonial civic building near Charleston's waterfront and descend to its Revolutionary War dungeon. The contrast between public exchange rooms and confined basement is the reason to go inside.

Built in the late 1760s, the Exchange served trade and government before British forces used its basement to hold prisoners during the Revolution. Its changing uses make the building more than a preserved facade: the rooms show how commerce, political power and wartime detention occupied the same site.

• The arched street-level openings and cupola of the Exchange
• The Provost Dungeon below the main rooms
• Exhibits on the building's colonial customs and exchange roles

Leave time for the cellar tour as well as the main-floor exhibits.

Pair it with a walk along East Bay Street to understand its former waterfront position.