For the Incas, the Aconcagua was a sacred mountain. As on other mountains (e.g. Ampato), places of worship were built here and sacrifices, including human sacrifices, were made. The sites discovered in 1985 at an altitude of 5167 m are among the highest in the world and are the most difficult of all Inca sites to reach. Here, the remains of a child bedded on grass, cloth and feathers were found inside stone walls (Aconcagua mummy). The clothing indicates that the child was a member of the highest social class. Other offerings found included figures and coca leaves.