Castle of Mystery It lay empty for 30 years because Rex refused to take phone calls from potential purchasers. With its primarily obscure history, the castle became known as Castle Farm. In 2003, the Martin heirs sold the property. The new owner intended to transform it into a bed and breakfast known as Castle Post. However, the plan was not pursued due to the onset of the economic downturn. Today, the castle remains unoccupied but is being preserved by the local government as a museum site. It is open daily except on Thanksgiving and Christmas Day. The castle's dark interior has been restored with period furniture and equipment. Exhibits include an art gallery, a dungeon, and a living room with a working fireplace. Near the castle are two other attractions: Fort Henry State Park and Old Fort Nelson. Both are free to visit. Fort Henry was built by the British in 1756 to protect the entrance to the Ohio River. After the American Revolution began, it became known as "Castle Clinton" because it was home to many loyal Americans. Today, the fort houses an exhibition on the history of Kentucky. Old Fort Nelson is a reconstructed military post that served as a prison for Indian fighters in the early days of Kentucky territory. The fort is located within its own park near downtown Louisville.