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 Mountain (Pennsylvania)
Blue Mountain Ridge, Blue Mountain, or the Blue Mountains of Pennsylvania is part of the geophysical makeup of the Ridge-and-Valley Appalachians in the U.S. state of Pennsylvania. It is a ridge that forms the southern and eastern edge of the Appalachian mountain range spanning over from the Delaware Water Gap as it cuts across the eastern half of the state on a slight diagonal from New Jersey tending southerly until it turns southerly curving into Maryland, and beyond.