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.
Belize Barrier Reef
In addition to its barrier reef, it also boasts three distinct Caribbean atolls: Turneffe Atoll, Glover's Reef and Lighthouse Reef. Lighthouse Reef is the most easterly diving area in Belize, it is home to the Great Blue Hole, made famous by Jacques Cousteau in 1970; Turneffe Atoll lies directly to the east of Belize City and is the nearest of the atolls to the capital. These different reefs provide diverse scuba diving opportunities that include walls, pinnacles and reef flats that are located throughout an enormous area of sea.