© UnknownThe 8th century monolith
Archaeologists in Mexico made a dramatic discovery in the state of Morelos when they uncovered an 8th century monolith featuring an Aztec God weighing 60 tonnes.

With agricultural images engraved on its side, the massive stone is believed to have been used by the Aztecs to call on the god of rain.

"These signs on the rock are fundamentally associated with agriculture and water. We think it's highly probable that it (the monolith) was used during rituals to ask for rain and it was placed in a position facing Popocatepetl," said archaeologist Raul Gonzalez.

With the ritual stone also bearing the image of the Aztec god Tlaloc, experts are connecting the massive monolith to the nearby archaeological site of Xochicalco.

"We have numbered them (hieroglyphics) all and those we have been able to decipher include a corn figure and one of Tlaloc," added Gonzalez. "We also have others which are anthropomorphous and others which are amorphous, which are four-legged animals. We don't know the exact definition or what they represent but they are there."

Reforma newspaper reports that construction workers building a shopping centre in the area first encountered the priceless artefact and notified authorities.

Further investigations by Mexico's Institute of Anthropology and History (INAH) unearthed the massive monolith near a highway connecting to the nearby city Cuautla. The scientists hope the 60-tonne monolith will have its final resting place at the UNESCO-listed Xochicalco zone.

The Aztecs, a warlike and deeply religious people who built monumental works, ruled an empire stretching from the Gulf of Mexico to the Pacific Ocean - encompassing much of modern-day central Mexico.

Their often bloody reign ended when they were subjugated in 1521 by the Spanish, led by Hernan Cortes.