Bermuda Triangle

The Bermuda Triangle (also known as the Devil's Triangle) is an area bounded by points in Bermuda, Florida and Puerto Rico where ships and planes are said to mysteriously vanish into thin air — or deep water.

The term "Bermuda Triangle" was coined in 1964 by writer Vincent Gaddis in the men's pulp magazine Argosy. Charles Berlitz, believed not only that Atlantis was real, but also that it was connected to the triangle in some way, a theory he proposed in his bestselling 1974 book "The Bermuda Triangle." The mystery has since been promoted in thousands of books, magazines, television shows, and websites.

There are lots of theories of the Bermuda Triangle like:

- The city of Atlantis is in the bottom of the Traingle, using it's "crystal energies" to sink ships and planes.

- Natural causes: Perhaps ships and planes are destroyed by pockets of flammable methane gas known to exist in large quantities under the sea or maybe lightning or an electrical spark ignited a huge bubble of methane that came to the surface right next to a ship or plane, causing them to sink without a trace.

-Others suggest sudden rogue tidal waves. Or maybe some mysterious geomagnetic anomaly that creates navigational problems confusing pilots and somehow causing them to plunge into the ocean; then again, pilots are trained to fly even with a loss of electronic navigation, and that theory doesn't explain ship disappearances. 

Source: http://www.livescience.com/23435-bermuda-triangle.html