Ongoing excavations at Templo Mayor (Great Temple), a now buried structure built by the Aztecs in their capital city Tenochtitlan (modern day Mexico City), have uncovered a large tower of at least 650 human skulls. The tower is thought to be the structure recorded by the invading Spanish conquistadores as the Huey Tzompantli. The skulls are mostly of men although the remains of women and children are also present. It has long been thought that the Aztecs and other Mesoamerican peoples performed ritualistic human sacrifices as offerings to the sun although there has been some argument about the veracity of this claim.
Photograph: Henry Romero/Reuters