The comparison sounds almost casual, but it became an important clue.

De Soto’s chroniclers described some houses in Capachequi in unusual language, comparing them to structures that appeared partly underground or cave-like.

For archaeologist Dennis Blanton, the match was striking.

The archaeological features were not literally caves.

They were the remains of earth-covered houses.

But the descriptions were close enough to suggest that the Spanish might have been describing the same kind of structures that archaeologists could see in the soil.

That was the beginning of a much stronger hypothesis.