Coral Castle is a stone structure created by the Latvian American eccentric Edward Leedskalnin north of the city of Homestead, Florida in Miami-Dade County at the intersection of U.S. 1 (South Dixie Highway) and Southwest 157th Ave. The structure comprises numerous megalithic stones (mostly limestone formed from coral), each weighing several tons.
The grounds of Coral Castle consist of 1,100 short tons (1,000 t) of stones found in the forms of walls, carvings, furniture and a castle tower. The stones are fastened together without any mortar. They are simply set on top of each other using their immense weight to keep them together. However, the craftsmanship detail is so skillful that the stones are connected with such precision that no light passes through the joints. The 8-foot (2.4 m) tall vertical stones that make up the perimeter wall have a uniform height. Even with the passage of decades and a direct hit on August 24, 1992 by the Category 5 Hurricane Andrew, which leveled everything in the area, the stones have not shifted.
Many of the features and carvings of the castle are notable. Among them are a two-story castle tower that served as Leedskalnin's living quarters, walls consisting entirely of 8-foot high pieces of stone, an accurate sundial, a Polaris telescope, an obelisk, a barbecue, a water well, a fountain, celestial stars and planets, and numerous pieces of furniture. The furniture pieces included are a heart-shaped table, a table in the shape of Florida, twenty-five rocking chairs, chairs resembling crescent moons, a bathtub, beds and a royal throne.
What is most remarkable about the contents of the Coral Castle is the massive size of the stones used throughout the construction, all the more remarkable when one considers that a single man assembled the entire site using only primitive tools. With few exceptions, the objects are made from single pieces of stone that weigh on average 15 short tons (14 t) each. The largest stone weighs 30 short tons (27 t) and the tallest stones are two monolithic stones standing 25 ft (7.6 m) high each.
A 9-short-ton (8.2 t) revolving gate is the most famous structure of the castle and was documented on the television programs In Search of..., and That's Incredible! The gate is carved so precisely that it fits within a quarter of an inch of the walls on both sides. It was so well-balanced that a child could open it with the push of a single finger. The mystery of the gate's perfectly balanced axis and the amazing ease with which it revolved lasted for decades until the gate suddenly stopped working in 1986. At that time, a team of engineers was brought in for consultation. In order to remove the gate, six men and a 50-short-ton (45 t) crane were utilized. Once the gate was removed, the engineers discovered how Leedskalnin had centered and balanced the 9-short-ton piece of rock. Leedskalnin had drilled a hole from top to bottom of the 8-foot-tall gate with no electric tools and inserted a metal shaft. The rock rested on an old truck bearing. It was the rusting out of this bearing that resulted in the gate's failure to revolve. The 9-short-ton gate, complete with new bearings, and a replaced shaft was lifted and set back into place on July 23, 1986. The gate failed again in 2005 and was subsequently repaired, however it does not rotate with the same ease it once did.
Edward Leedskalnin was jilted by his 16-year-old fiancée Agnes Scuffs in Latvia, just one day before the wedding and traveled to America. Edward spent over 28 years building the Coral Castle, refusing to allow anyone to view him while he worked. The only tool that Leedskalnin spoke of using was a "perpetual motion holder." Leedskalnin never told anyone that asked him how he made the castle. He would simply answer "It's not difficult if you know how." If asked why he had made this castle, Leedskalnin would vaguely answer it was for his "Sweet Sixteen."
From: http://en.wikipedia.org/wiki/Coral_Castle