Everyone knows that stone walls cover the New England landscape like honeycombs. But far fewer 
people know about the region’s hundreds of mysterious stone structures.
In the 1930s, someone estimated that New England had 250,000 miles of stone walls. In the following decades came inventories of the region’s stone structures, which some believed to be ancient.
A stone chamber in Leverett, Mass.
Some of those ancient stone structures are oriented to the stars and planets. They also stand near megaliths, cairns or dolmens. A few have what are probably stone beds or sacrificial altars.
Speculation now runs rampant about the origins of the mysterious stone structures. Did medieval Irish monks, American Indians or Vikings build them? Or did the English colonists just built them as root cellars?
Most noteworthy, just three Northeast counties account for the majority of stone structures in North America: Putnam County, N.Y.; New London County, Conn.; and Windsor County, Vt.
Massachusetts has the densest concentration of beehive-shaped stone chambers like those built by Culdee monks in Ireland. The state has 105 sites containing stone structures.
Connecticut also has quite a few at 62, New Hampshire has 51 and Vermont has 41. Tiny Rhode Island has only 12 stone structures, but still more than Maine, which has only four.
Some speculate that perhaps ancient voyagers frequently traveled the Merrimack, the Thames and the Connecticut rivers. They then built their stone structures along those routes.
Here, then, we bring you ancient stone structures (or maybe colonial root cellars), with at least one in each New England state.
Gungywamp, Groton, Conn.
Gungywamp stone circle
New England colonists found many stone buildings, when they arrived. Typically they were one story high, circular or rectangular and as long as 30 feet. Many had roof openings that allowed a little light to illuminate the interiors.
As a result, early mercenaries to the Northeast wrote about ‘Indian stone castles.’ Furthermore, John Winthrop the Younger in 1654 received a letter from John Pynchon of Springfield, Mass. Pynchon heard ‘a report of a stone wall and strong chamber in it, made all of stone, which is newly discovered at or near Pequot.’
The 100-acre Gungywamp archaeological site in Groton, Conn., contains such stone structures as beehive chambers, petroglyphs, a double circle of stones, cellars and walls. All date back hundreds of years.
Some of the structures are thought to be Native American and perhaps had ceremonial functions. Colonial settlers built others with purposes such as root cellars and birthing chambers. Some features of the site suggest they were originally built as fortifications.
There is plenty of speculation about the purpose of the Gungywamp stone structures. Some theorize that 8th-century Irish monks built certain structures. They argue ‘Gungywamp’ means ‘church of the people’ in Gaelic. Others say it is an Indian word.
Gungywamp’s most famous chamber is the so-called ‘calendar chamber.’ Archaeologists suspect the colonists originally used it for storage for a nearby tan bark mill. A vent at one end of the chamber aligns with the spring and fall equinoxes. It thus allows a shaft of sunlight to fall directly on a smaller chamber within the larger structure.
Gungywamp is preserved, but many of the structures stand on private land. It can be toured virtually here. Visitors can tour the Gungywamp through the Denison Pequotsepos Nature Center. More information is available here.
Hirundo Stone Structures, Alton and Old Town, Maine
Hirundo Wildlife Refuge
The Red Paint people of Maine once settled in the Hirundo Wildlife Refuge, a wetland preserve. Archaeologists discovered artifacts from the 7,000-year-old village along the Wabanaki Trail.
Among the bogs and ancient burial grounds are at least 18 curious stone piles, clearly made by humans. But by whom and for what? And when? No one know. Most are 6-1/2 feet in diameter and a foot and a half high.
The University of Maine owns the Hirundo Wildlife Refuge, which is open dawn to dusk all week long.
Upton Stone Chamber, Upton, Mass.
Nashoba Brook Chamber
The largest and probably best known stone chamber in Massachusetts is the Upton Stone Chamber near Worcester in Upton.
It includes a tunnel that connects to a roundish beehive room. A stone slab sits on top. In 1989, two archao-astronomists concluded that people used the chamber between 700-750 A.D. to study the Pleiades. Around 670 A.D., they used it to view the summer solstice.
To see photographs from 1944 of the Upton Stone Chamber, click here. The Upton Heritage Park is at 18 Elm Street.
Thirty miles away in Acton, an underground stone chamber in the Nashoba Brook Conservation Area is known as the ‘potato cave.’ Residents had long assumed the structure was a root cellar. A 2006 excavation found evidence people stored food in it in the 18th or 19th century. Some argue Indians built it before the colonists arrived. Still others say railroad workers lived in it during the 19th century.
You can visit the restored chamber at the Nashoba Brook Conservation Area in North Acton on the easterly side of Main Street (Route 27), toward Westford and Carlisle.
American Stonehenge, Salem, N.H.
America’s Stonehenge
During the summer solstice, a procession of people banging drums softly come to America’s Stonehenge. They aim to honor Mother Earth.
America’s Stonehenge is a 30-acre complex of standing stones, underground chambers and stone walls in North Salem, N.H. As the largest collection of stone structures in North America, it includes dolmens, or horizontal stone slabs on vertical stone uprights. It also has cromlechs, or circles of standing stones and barrows, or tombs. There’s a secret bed, an echoing oracle chamber, a sacrificial altar stone and a stone-lined speaking tube that gives the impression the altar is talking when someone speaks into it.
Radiocarbon dating confirms that the structures were built as many as 4,000 years ago.
The written record doesn’t mention the ancient stone structures until 1907, in History of Salem, New Hampshire by Edward Gilbert. He wrote that a family named Pattee owned the land, called Mystery Hill, and had many of the stones carted away for construction in Lawrence, Mass.
A retired insurance executive named William Goodwin bought the site in 1937. He had it excavated and became convinced Irish Culdee monks built the site about 1000 A.D. The monoliths are astronomically aligned, leading to the conclusion the stones were used as a prehistoric calendar.
Mystery Hill was renamed America’s Stonehenge and as a result gets 15,000 visitors a year. The site can still be used as an accurate yearly calendar.
Queen’s Fort, Exeter, R.I.
Queen’s Fort
The Queen’s Fort and Queen’s Bed Chamber in Exeter, R.I., have colorful legends about them. In its later years, the Queen’s Fort supposedly sheltered hermits and bandits.
Archaeologists and historians associate the fort with a man named Stonewall John, a talented stone mason who may have been Narragansett or English. He may have built the stone fort to protect King Philip during King Philip’s War (1675-78). The colonists made one of their first attacks on the fort during the war.
Within the fort a chamber – six square feet with a seven-foot ceiling and a sand floor – was perhaps built for the Narragansett queen Quaiapen (also called Matuntuck). She supposedly hid out at the site during King Phililp’s War before moving somewhere else, where she died. Some have also suspected that Quaiapen and Stonewall John were lovers.
Many archeologists have since dug at the site. Today the Rhode Island Historical Society owns it, and the National Register of Historic Places includes it on its list. You can get to it via a series of trails in Exeter that surround the property. Find more information here.
Stone Structures in South Woodstock, Vt.
Eastern Vermont has some of the densest concentrations of ancient stone structures in North America. An inventory of Vermont’s stone chambers compiled by the New England Antiquities Research Association found 52 stone chambers. They discovered them in 23 towns in five Vermont counties, particularly Orange and Windsor.
In 1975, a retired marine biologist from Harvard announced his discovery: On Vermont’s stone structures he found inscriptions in a dead Celtic language called Ogam. He concluded Celts from the Iberian peninsula carved them around 1000 BC. They all faced east and many had inscriptions. And some have symbolic markings, while others have Celtic place names.
But critics of the theory counter that Celts would have left other evidence that they’d settled in New England. But no one found any such evidence.
Still, Vermont farmers told stories of their great-grandfathers’ plows uncovering stone huts. So in 1977, the Vermont Division for Historic Preservation studied the stone chambers in the state. They concluded the stone structures did not serve as stone burial vaults, charcoal or lime kilns, potash burners or iron furnaces.
One of the biggest and best known stone chambers is called Calendar II in South Woodstock, Vt. Calendar II measures 10 feet by 20 feet on the inside, the same geometrical ratio as the King’s Chamber of the Great Pyramid. And the door aligns with the solstice sunrise.
A Norwich University professor studied aerial photographs of Vermont and discovered another mystery. He found odd hexagonal patterns made of stone walls and ditches. But many had no relation to current and traditional land use patterns. The mystery remains unsolved.
Notes on Mysterious Stone Structures
Images: Gungywamp By Randal J. (en:User:RJFerret) – Own work (own photo), CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=7714677; Nashoba Brook Stone Chamber, By John Phelan – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=20548479; Leverett Stone Chamber By BittyRed – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=46106121; American Stonehenge, By Stan Shebs, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=123562; Queen’s Fort, By JERRYE & ROY KLOTZ, M.D. – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=49496088; Stonehenge CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=195581. Hirundo Wildlife Refuge By Namiba – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=69290251.
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This story about mysterious stone structures was updated in 2025.
