The Bermuda Triangle was an area on Earth in the Atlantic Ocean where a number of ships, airplanes, and people have vanished over the years.
Captain Jonathan Archer once likened the Delphic Expanse to the Bermuda Triangle. (ENT: "The Expanse")
The Delta Triangle in TAS: "The Time Trap" appears to have been named after the Bermuda Triangle.
The area also was mentioned in the Star Trek: Voyager - Elite Force video game.