In early times the people of Rapa Nui reportedly sent the dead out to sea in small funerary canoes, as did their Polynesian counterparts on other islands. They later started burying people in secret caves to save the bones from desecration by enemies. During the turmoil of the late 18th century, the islanders seem to have started to bury their dead in the space between the belly of a fallen moai and the front wall of the structure. During the time of the epidemics they made mass graves that were semi-pyramidal stone structures.