Daylight penetrates just the first few feet of the tunnel that leads into the "Upton Chamber," the mysterious man-made cave in Upton. Then the stone walls and murky water underfoot disappear into darkness.
Jerry Owczarzak, a member of the Upton Historical Commission, rolls his jeans up over his combat boots and flicks on his battery-powered lantern. He stoops to enter the tunnel's 3 -foot-tall mouth.
"You don't know what it is, you don't know how old it is, you don't know who built it," says the husky, bearded Owczarzak. "There's probably as many theories as there are people who ask questions."
The town purchased the land surrounding the cave from a private owner last year, and the Historical Commission agreed to give a reporter a tour of the puzzling structure.
After squeezing through the opening, Owczarzak is able to stand almost upright in the approximately 14-foot-long tunnel that leads to a taller, beehive-shaped dome. Dead leaves cover the floor, and about 6 inches of collected rainwater slosh around Owczarzak's boots and slap against the stones as he makes his way through.
The lantern and an accompanying flashlight reveal the detritus of previous expeditions. A couple of boards float around the tunnel -- probably tossed in by children, or laid across the water by bootless explorers, Owczarzak says. A lost sock sticks to the muck of the floor.
"That's not a Viking sock," Owczarzak jokes, a reference to one of the myriad theories about the origin of the structure.
Barbara Burke, chairwoman of the Historical Commission, says the chamber is perhaps three centuries old. She bases that on an 1893 newspaper article, which states that elderly residents at the time said their ancestors had talked of the cave and and did not know who built it.
Some say Colonial settlers might have used the chamber to store ice or vegetables. Others think it may have been a Native American ceremonial site.
Malcolm Pearson, 96, of Sutton was a teenager when his father bought the land in 1928. He thinks the structure sheltered European settlers who came to the New World between 2,500 and 3,000 years ago.
"All you have to do is go into England and Scotland, and you'll see places exactly like the one they have here," Pearson says.
Alan Leveillee, a senior archeologist with the Public Archaeology Laboratory Inc. in Pawtucket, R.I., a nonprofit organization that consults on archeological sites in New England and the Middle Atlantic states, says the site is worth preserving, even though no one knows for sure who built it or when.
He says town officials should first examine whether the structure is from Colonial times, because that would be the simplest explanation. "I think before you move on to more complex things to prove, you look into that."
While others may disagree, the general consensus among professional archeologists is that there's no evidence of pre-Columbian European settlers in New England, Leveillee says.
David H. Kelley, an emeritus professor of archeology at the University of Calgary, studied the chamber in the 1950s while working toward his doctorate at Harvard. He says he believes that there were unrecorded pre-Columbian European settlers in North America, a belief that he acknowledges goes against the grain of his profession. Still, he says the Upton chamber is likely a Colonial structure.
"There were times when I thought that [the chamber] might be pre-Columbian, but the more I've thought about it, the more I become convinced that it wasn't."
Kelley found a silver button during his excavation, and tests dated the item to Colonial times. The structure probably was built by someone with knowledge of similarly constructed ancient sites in Brittany, he says.
The structure sits on an approximately 7-acre parcel. Volunteers will begin clearing the land this summer, as the town works to turn it into a park. In addition to the overgrowth of olive trees and bamboo, Burke says, an Elm Street house needs to be either moved or demolished.
The vacant house sits on the town's only access point to the land. The rest of the parcel is surrounded by private property and by Mill Pond, which the town also owns.
The town plans to create walking trails and build a gazebo on the land, and to create a canoe launch on the pond. Even when the park opens, Burke says, residents won't be able to explore the mysterious chamber without supervision by town officials.
Except for the tunnel opening, the whole structure is covered with earth. The site can be reached by walking up the driveway of the Elm Street house, then through tall grass and into the woods. The structure looks like a mound of dirt at the intersection of two stone walls, which Owczarzak says were built long after the chamber. Maple trees and saplings grow thick in the area, with one large tree sprouting from the top of the "beehive" chamber.
Just as no one knows the origins of the structure, Owczarzak says, it's unknown when it became covered by earth.
Owczarzak will only give tours if someone stands outside the chamber, ready to run for help in case of a sudden collapse of the structure or the entryway. Indeed, the large rock that sits atop the entrance has, at some point over the years, shifted about a foot downward on one side.
Inside the chamber, the irregularly shaped wall stones range from a few inches in diameter to rocks 5 or 6 feet wide. They are stacked on top of one another, each layer jutting slightly farther into the chamber until the walls nearly converge about 10 or 12 feet from the ground.
At the top of the chamber is an opening about 3 feet wide, covered by a flat capstone. A sweep of the lantern shows some spiders hanging in undisturbed webs.
The town is working on unraveling the mystery, Burke says. She hopes the state Historical Commission will conduct tests soon that will help determine the age of the structure.
Although she longs to know who built the chamber, Burke says, part of the charm lies in the unknown. "Half of the whole idea is the mystery behind it," she says. "Everybody can see the cave and decide for themselves what they want to believe."