Inhumations in tumuli occur in western Greece from the end of the EH II and particularly during the EH III period. Researchers connect them, with certain reservation, to the movements-penetrations of populations from the west Balkans (Dalmatia, Albania) in southwestern Greece about the end of the EH II. During the MH period this custom is applied more often in the greater south Helladic region.

The most important examples of tumuli were found in Olympia (Pelopeio) and in Nidhri of Lefkas. The 33 tumuli which were excavated in Nidhri and are known as tumuli R, constitute a cemetery used about the end of the EH II (seven tumuli) and during the EH III period. These burial monuments are constituted of layers of earth and stones and are defined by circular stone walls. The diametre of the tumuli varies from 2,7 to 9,6 metres. Each of them received a different number of dead persons. In total 62 burials of children and adults in simple or built pits, cist graves or in pithoi have been examined while some incinerations also took place. Among them four burials of women and three of men are distinguished. These contained rich grave goods: a gold necklace, a silver bracelet and bronze swords.

The tumulus which presents similarities with the tumuli R is the one examined in the area of the New Museum of Olympia (Pelopeio). The tumuli excavated in the area Altis of Olympia, in Lerna IV and in Thebes (Ampheion) and date to the end of the EH II have a different construction from the burial ones. They do not contain burials and seem to be of a symbolic-ritual character.