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)
The Blue Hole is dived almost every day by recreational divers. Local dive centres take divers who are qualified to dive to 30m (AOW level or CMAS**) to do the site known as El Bells or Bells to Blue Hole. The entry is from the shore further along from the Blue Hole at an entry called The Bells. At 26m at the bottom of the Bells is a mini arch that should not be confused with the arch in the Blue Hole itself. The dive is then a wall dive that finishes crossing the Blue Hole saddle at a depth of 7m. Recreational divers do not get to see the Blue Hole arch when doing the Bells to Blue Hole dive.