Researchers at the time described the tower as standing some 25 feet (7.5 meters) tall, with outer walls 6 feet (2 meters) thick. Today only about 12 feet (3.5 meters) of the structure remain.

When the tower was found, it held the remains of 16 men, women, and children, all of whom bore signs of gruesome deaths.

The fortified structure is another insight into the violence that plagued the Gallina, a culture that thrived in the region from about the 11th to the 13th centuries before mysteriously disappearing.

"Probably the most famous thing about the Gallina is the towers they made," said Tony Largaespada, a U.S. Forest Service archaeologist. "[People] call them Gallina towers, and they almost looked like medieval European castles."

A handful of other towers have been found nearby but nowhere else in the Southwest, he said.

"No other people made those," Largaespada said. "They're unique."

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