Archeologists working near the Georgetown waterfront yesterday uncovered the ruins of three 18th century buildings that may yield new insights into the once-busy port city.

And no sooner had they found them than they quickly covered them back up.

The ruins, which archeologists said could have been anything from tobacco warehouses to saloons, were unearthed near the waterfront near 31st and K streets NW. Archeologists said the buildings date to when the Georgetown harbor was an international shipping and trading port in the 1700s.

The archeologists -- a six-member team sponsored by the Washington Harbour Associates, a group of private developers -- extracted brick and soil samples before shoveling soil back over the block-long dig to protect it until the National Park Service decides what to do with it.

"This harbor was the lifeblood of Georgetown in its day," said Stephen Potter, regional archeologist for the Park Service. "Warehouses, shops, and retail and wholesale businesses filled this area."

The site is just below the Whitehurst Freeway and just west of the Washington Harbour, a commercial and condominium complex under construction.

The Park Service granted Washington Harbour Associates the right to construct another complex containing a hotel and offices on the Georgetown waterfront in exchange for providing a public walkway and landscaping along the Potomac River and Rock Creek. The site is slated to become a waterfront park once the District turns the land over to the Park Service, which will oversee construction.

The dig is six feet deep and contains the foundations of three red-brick buildings. The remains of the buildings' walls rise only three feet, revealing floors of red brick arranged in a herringbone pattern. Between the structures are two well-preserved cobblestone streets.

Janice Artemel, a member of the archeology team that discovered the ruins, said the dig had to be refilled because funds are not yet available to continue the excavation. She and her colleagues will submit a report on their findings to the Park Service, which will then consider the team's recommendations in planning the park.

"This is the first glance we've had of the 18th century in the District , said Artemel. "I hope that it will be shared with the public when the park is constructed."

Donald H. Shannon, a reporter who once headed the Citizens Association of Georgetown, said that making the ruins part of the proposed park would be in the public interest because the area was "the first European settlement in the New World."

"Anything like this is of historical importance and is relevant to today," said Shannon.

Earl Kittleman, a Park Service spokesman, said that the archeologists' recommendations will be considered before plans are made for the park. "We're not at that stage yet," he said. "We don't even have a budget on that yet."

Many factors have to be weighed, he said, "when planning a park in so visible a place."