In Episode 73, Jeff Belanger and Ray Auger explore a mysterious hill in Salem, New Hampshire, called America's Stonehenge. This stone site seems to be a celestial calendar that marks solstices, equinoxes, but also half-holidays. It's a sacred site that may be up to 4,000 years old. But who built it? Were human sacrifices practiced here? Stone sites like this one shake the foundation of our history books.