If it is man-made (rather than a natural formation), it could require a reevaluation of history. The nearby Caddo Native American tribe has no history of building such structures, and it's commonly accepted that they were also incapable of building the structure. "After compiling past records, data, and documents, including recent studies and research, evidence of a prehistoric structure built by man is mounting," said Architect John Lindsey in 1996, according to the Rockwall County Historical Foundation.