Evidence that the Chipaya migrated from Central America is seen in their orientation to the four cardinal directions, their yearly religious calendar, and their use of the corbeled arch in native architecture. Migrating southward, they were presumably forced up onto the highland plateau and gradually moved, and/or were moved, to their present location. They value their freedom more than they do better land. Documents dated as far back as 1722 show conflict with the surrounding Aymara. This conflict was finally settled in the 1970s when the Chipaya permanently lost more land to the Collana ayllu of Aymara. Because of close contact with the Aymara, the Chipaya have assimilated some of their cultural practices. The culture of the Inca Empire has also influenced the Chipaya. An old Inca burial ground is traditionally identified as the original Chipaya settlement, and there are some loanwords from Quechua that are not cognate with Aymara. A common belief in the area is that the Chipaya came from the Chullpa, an ancient people, probably Quechua, because the clothing on mummified Chullpa bodies is similar to Chipaya clothing.