What is "gungywamp"

Gungywamp is an archaeological site in Groton, Connecticut, United States, consisting of artifacts dating from 2000-770 BC, a stone circle, and the remains of both Native American and colonial structures. Among multiple structural remains, of note is a stone chamber featuring an astronomical alignment during the equinoxes. Besides containing beehive chambers and petroglyphs, the Gungywamp site has a double circle of stones near its center, just north of two stone chambers. Two concentric circles of large quarried stones - 21 large slabs laid end to end are at the center of the site.