The Mystery of Coral Castle
In Leisure City, Florida lies the only modern monolithic structure in the world.
It was first built in Florida City. Florida by Edward Leedskalnin in 1923 with blocks weighing as much as 30 tons and without any heavy machinery. He claimed to know the secrets of how the pyramids were constructed and he built Coral Castle to prove it.
In 1936 Edward decided to move and he took his castle with him, armed with only a small mysterious box, he managed to load the entire castle onto trucks within the truck drivers lunch break. Coral Castle is currently a tourist destination that everyone should visit.
I've been there several times. It's an amazing place. The front gate is mounted on an axle and swings open with the lightest touch. Everything in there has some symbolism. Supposedly Edward built it to memorialize a lost love. Check this out if you're in the Miami / Keys area.