Mystical Horizons: 21st Century Stonehenge
Bottineau, North Dakota
This remotely located solar calendar of astronomically configured boulders and a sundial was the vision of pilot Jack Olson, who died four years before it was completed in October 2005. He had picked this exact spot in the Turtle Mountain Recreational Forest, but it wasn't until the various pillars and monuments -- most made of brick -- were erected that engineers realized that Olson had chosen the only place in the region with the coordinates and elevation that would have worked.
Mystical Horizons is a popular spot on the solstices and equinoxes, but it remains quiet for the rest of the year.