As construction of the final stage of a $600 million development in downtown Miami drew near, Miamians looked forward to getting a new 34-story hotel, with movie theaters and restaurants, on what had been a vacant two-acre lot.

What they got instead at Met Square was a landmark archaeological discovery and a roiling controversy.

It turns out that Tequesta Indians, who inhabited southern Florida for some 2,000 years, built a sizeable village on this site 1,500 years ago, and its signature features are virtually unique: postholes for circular buildings, drilled directly into the limestone bedrock.

The only other place these kind of postholes have been found in North America, says Robert Carr, the lead archaeologist for the excavation, is the Miami Circle, a site less than a half mile away (which he also discovered in 1998). Faced with a lawsuit by preservationists, the would-be developer of that site backed down and sold the property to the state.

The Miami Circle is now a National Historic Landmark, and with the Met Square site also a likely candidate for landmark designation, the developer, MDM Development Group, and preservationists are battling over the site's future. At stake: millions of dollars, versus a rare portal into a vanished past.

"The Tequesta were the earliest group to establish permanent villages in southeast Florida," says Jeff Ransom, Miami-Dade County's archaeologist, who has concurred with Carr's conclusions about the site. With thousands of postholes outlining the circumference of eight buildings, each roughly 40 feet in diameter, Carr estimates that up to a thousand people once lived in the ancient village, which extended a half mile along the north bank of the Miami River, near its confluence with Biscayne Bay.

"It's so unusual to actually have the settlement plan preserved like that," he says. He has also discovered the remnants of structures that appear to be elevated platforms—perhaps boardwalks.

View Images A man holds a tool made from the center spiral of a conch shell, found on the newly uncovered site of a Tequesta Indian village. PHOTOGRAPH BY JOE RAEDLE, GETTY IMAGES

Tequesta Culture Complex, Unusual

"This is not the general picture people once had of roaming bands of Native Americans foraging in the Everglades," Carr says. "These people were more complex, with larger towns and a more sedentary lifestyle."

But unlike most sedentary cultures, the Tequesta didn't practice agriculture. Because the climate was warm year-round, the Indians subsisted on a reliable diet of seafood and native plant foods, enjoying a level of sociopolitical complexity that becomes possible when you're not on the move all the time. "That's rare," Ransom says. "They had a chiefdom without agriculture. You don't see that in other parts of the United States."

What's also rare about the Tequesta, says Ransom: "They thrived even 200 years after contact with Europeans. They were one of the first Native American groups encountered by Ponce de León when he came here in 1513. The historical records show he encountered them in Biscayne Bay—so this is possibly the site he saw."

The Tequesta were gone by the late 18th century. First European diseases like smallpox took a heavy toll; the survivors left Florida for good when the British took control from Spain in 1763. "They didn't want to be enslaved, and that's what was going to happen," Ransom says. It's believed they resettled in Cuba.

Seminoles have claimed the Tequesta as ancestors, but their surest legacy at this point is archaeological. That, says Carr, is why this site is so significant. "Most of the area downtown has already been destroyed by development," he says. "This is the last location where a site has survived."

View Images An archaeologist works at the Miami site, which may be one of the most significant prehistoric sites in the United States. PHOTOGRAPH BY LYNN SLADKY, ASSOCIATED PRESS

Fate of the Rare Site

What happens next is unclear. State and county preservation officials would like to see the Met Square development plans revised, but the decision ultimately rests with the city of Miami.

In February, Miami's Historic and Environmental Preservation Board rejected MDM's proposal to remove a portion of the postholed bedrock for a visitor exhibit and proceed with the development as planned, arguing that it's insufficient protection for such a historically significant site.