After being rejected by his fiancée and coming down with tuberculosis, Edward Leedskalnin spent 28 years building the Coral Castle, a colossal oolite limestone structure
Composed of over 16 million bricks, Fort Jefferson in Florida is the largest abandoned brick structure in North America
Built in the early 1800s by the Bulow family, this once proud factory and mansion was burned to the ground during the Second Seminole War and fell into ruins