At the Templo Mayor Aztec complex in Mexico City's historic centre, archaeologists have unearthed a trophy rack for sacrificed human skulls. According to officials, the platform known as "tzompantli" (sohm-PANT-lee) measures between six and eight metres and was used by the ancient Aztecs to display a rack of severed heads held together with a wooden pole.

A warlike and deeply religious people, the Aztecs used human skulls, which were typically from war captives, as a show of strength and symbolism. The Aztecs ruled an empire stretching from the Gulf of Mexico to the Pacific Ocean, encompassing much of modern-day central Mexico.

"The tzompantli had a very specific symbolism. It was an indication, in a certain way, of Mexica power," said archaeologist Raul Barrera Rodriguez. "Generally, the skulls of decapitations from several ceremonies would be exhibited in the tzompantli. Sometimes, these ceremonies also took place with Mexicas. Through studies, we are expected to detect that many of these skulls belong to enemies of the Mexicas, who were captured, sacrificed and who were decapitated in order to be displayed there."

The tzompantli was found near the Templo Mayor, the largest and most important temple of the Aztec capital of Tenochtitlan, which was used for religious ceremonies and human sacrifices. The discovery could help archaeologists better map out the lost city of Tenochtitlan, razed by the Spanish in the 16th century after the Aztecs surrendered.

"The information we are obtaining now from these buildings is that, at least the Temple of Jeca, the game of ball and the tzompantli, we know their correct location," said archaeologist Eduardo Matos Moctezuma. "We think that information is very relevant because it is showing us the relation that exists between those buildings and the Templo Mayor. We know the tzompantli has to be related to huitzilopochtli and with the game of ball."