Wanda in West Virginia wrote:

They are Indian burial mounds. When originally constructed they were
approximately 25-35 feet high, but have eroded over the centuries. If
you dig into them you will find tiny Indian skeletons, miniature peace
pipes, and other small artifacts.

Maybe the bodies were buried upright, and it really *is* a burial ground
.... dig a foot down, and the round white tops of skulls might show.

--
Farlo, the Urban Fey Dragon