they make it out of tons of dirt, stone or rock.
They are earthen mounds.
I think they built mounds for religious purposes and as cemetaries for the dead .
The Mound Builders built mounds of earth and stone
Building mounds.
the building of mounds
The Indian Mound Builders built mounds for elite residential purposes, burials and religious and other ceremonials. The mounds were usually flat-topped pyramids or platform mounds.
They used the mounds as graves and for important ceremonies.
they built mounds
they sometimes built mounds
//
//
my mom