Blue Hole (Castalia)
The Blue Hole is a fresh water pond located in Castalia, Erie County, Ohio, in the United States. From the 1920s to 1990 the Blue Hole was a tourist site, attracting 165,000 visitors annually at the height of its popularity, partly because of its location on State Route 269, about southwest of the Cedar Point amusement park in Sandusky, Ohio.
Blue Hole (Red Sea)
However, the Blue Hole is notorious for the number of diving fatalities which have occurred in the past. One local Tech-Diver puts the number of deaths over 130-200, and thus claims that it is the most deadly dive site in the world.