9Coral Castle, Florida, USA

Hidden in Homestead, Florida, Coral Castle was built by one man—Edward Leedskalnin—using over 1,000 tons of coral rock. What makes it extraordinary is that he constructed the entire site without help or heavy equipment. Leedskalnin claimed he possessed secret knowledge of magnetism and the forces of nature. Some believe he unlocked ancient techniques similar to those used in pyramid construction. The mystery of how he moved and sculpted the massive stones remains unsolved.