The cliff tombs of the Chachapoya
The Chachapoya people went to great lengths to care for their dead. In the remote site of La Petaca in northern Peru, a 300m cliff contains caves used as tombs. It isn't fully understood how the Chachapoya managed to build halfway up these cliffs, but there's evidence that they extended the entrances to many of the caves. Inside, skeletal remains have lain undisturbed for at least 500 years. Some of the rock has been worn smooth, suggesting repeated visits, and the bones themselves have been carefully and deliberately positioned. It's thought that the people went to such lengths to protect and care for the dead because displaying their ancestors' remains reinforced territorial claims.