One of the attractions of Mexico is its rich ancient history which is still shrouded under many layers of mystery. Archaeologist continue to find stunning discoveries which reveals so much about Mexico's past yet amazes us that we still know so little of our ancestors. If many tourists come to to Mexico only for it's beaches in destination like Playa del Carmen, a sizeable portion of them also come to know more about Mexico's glorious past.

Recently, a huge pile of skulls has been discovered at the most sacred temple of the Aztec empire dating back more than 500 years. Experts believe that this discovery throws new light on ways the pre-Colombian civilization used skulls in rituals at Mexico City's Templo Mayor. This excavation itself is a milestone as never before such numbers skulls were found in one offering.

The most important Aztec ceremonies took place at Mexico City's Templo Mayor between 1325 until the Spanish conquest in 1521. The 50 skulls were found at one sacrificial stone. Five were buried under the stone, and each had holes on both sides which imply that they were hung on a skull rack.

Archaeologist Raul Barrera of Mexico's National Institute of Anthropology and History said the other 45 skulls appeared to have just been dumped on top of the stone. Barrera said they believe the 45 skulls were those of women and men between 20 and 35 years old and could have been dug up from other sites and reburied.

The skulls were in good condition and just have sustained few cracks on each side of the head, possibly because of the wooden stake that ran through them so they could be placed in a skull rack. Barrera said the key in the discovery was the sacrificial rock, which looks like a gray headstone.

"Underneath the sacrificial stone, we found an offering of five skulls. These skulls were pierced with a stick," he said. "These are very important findings.

"University of Florida archaeologist Susan Gillespie, who was not involved in the excavation, said it caught her attention that the skulls that had been on the rack, called tzompantli, were buried separately.

"It provides rather novel information on the use and reuse of skulls for ritual events at the Templo Mayor," Gillespie said in an email.

Also, the common belief about Aztec sacrificial stones is that, a person being sacrificed was killed by cutting open the chest and pulling out the heart.

"We normally associate (it) with heart removal rather than decapitation," she said. "It ultimately gives us a better understanding of how the Aztecs used the human body in various ways in their ritual practices.