In North Groton, Connecticut lies the archaeological enigma known as Gungywamp. It is an interesting ancient complex. Dating back to pre colonial times, some accounts place it as far back as 2,000 BC. Nobody is even sure as to the meaning of its name 'gungywamp'. One of the native tribes, the Mohegan, believe it is a derivative from their language meaning 'place of ledges', while another native tribe of the region, the Pequot, claims it means 'swampy place in theirs.
An early colonial reference to Gungywamp comes from 1654 letter from the governor of colonial Connecticut, about a stone wall and fort located at Gungywamp.
The site consists of assorted stone structures of uncertain origin. Native Americans of the area are not known to have built with stone. It is divided into 2 primary sections one in the north and south. The structures consist of a double circle of stones, standing stones, and stone chambers. They aren't on par with the Great Pyramids, but they are sometimes called America Stonehenge.
One theory states that gungywamp only dates to circa 600 A.D. and was created by Celtic - Culdee monks from Ireland. Which is fitting as the site is reminiscent of similar druidic structures in the British Isles and Brittany.
The Druids were avid astronomers who plotted the motions of the heavens. They predicted eclipses, and knew the dates of equinoxes and solstices. It is apparent that the engineers of Gungywamp shared the druids astronomical beliefs as the constructs have been demonstrated to have strong relevance to heavenly alignments.
One chamber in particular that catches the suns rays has 4 solar alignments and the fall and spring equinoxes as well as summer and winter solstices. The chamber basically serves as an ancient calendar. The possibility of these alignments being accidental are ludicrously slim.
Another chamber near the 'Cliff of tears' has strange physiological affects on people ranging from nosebleeds, dizziness and nausea to strong headaches. Some people who visit spontaneously start crying with no apparent reason.
Investigation has revealed an intensely strong electromagnetic field due to large deposits of reverse polarity iron ore in the form of magnetite combined with granite and quartz. The electromagnetic abnormalities may help to explain the physiological reactions on visitors. Some have claimed that paranormal activity occurs there and have advanced theories the place serves as an inter dimensional buffer.
Several similar sites exist scattered about New England. The Upton Cave in Massachusetts, Goshen Chamber in Massachusetts, Oracle Chamber of New Hampshire, New York, Vermont and Maine all host enigmatic constructs that defy explanation via conventional archaeology.