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 Whale Harbour
Blue Whale Harbour () is a small, sheltered anchorage entered west-southwest of Cape Constance, along the north coast of South Georgia Island. It was charted in 1930 by Discovery Investigations personnel. It is named for the blue whale, a commercially important species which was once widely distributed in polar and subpolar waters; numbers are now very small.