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.
Cyanea dolichopoda
This Hawaiian lobelioid was discovered in the Blue Hole, a valley on Kauai near the Wailua River. The Blue Hole is deep, nearly surrounded by steep cliffs up to 900 meters tall, and wet, a very high rainfall area filled with waterfalls. Only four plants were ever found, three juvenile specimens and one plant just reaching flowering stage. Because the plant was so obviously an unknown species and was apparently on the brink of extinction, it was given a name. It was not seen again after 1992.