Directly behind the courthouse, this granite structure has two foot thick walls, two stories and a trap door above the entry. Condemned prisoners were hung above the trap door and dropped to their death. The building has remained virtually unchanged with its castellated roof-line, sloping stone walls, and fortress-like appearance since its completion in 1807. It is believed to be the oldest existing jail structure in the state. The cells are veritable dungeons without light or ventilation except for the grated doors downstairs and the small grated windows above. The jail was used until the 1890's.