The Old Barracks is the only surviving colonial-era barracks building in the United States. Built in 1758 to house British troops during the French and Indian War, it was later used by Hessian soldiers before Washington's surprise attack on Christmas night 1776. The museum operates as a living history site: costumed interpreters demonstrate 18th-century military life, and the furnished rooms give a genuine sense of what the soldiers' quarters looked like.
The building sits just south of the State House on Barrack Street — you can walk between them in five minutes. Admission is around $8 for adults. Closed Mondays.