The Aztecs were a Mesoamerican culture that flourished in Central Mexico in the period between 1300 to 1521. They were made up of multiple different ethnic groups of the region, especially those who spoke the Nahuatl language. Aztec culture was organised into city states, some of which joined to form alliances, political confederations and even empires.
These large cohesive social creations left their mark on the land, most often in the form of great cities and stone structures, like pyramids and temples.
Many of these pyramids remained elusive to researchers for years, but recently, modern technology has enabled researchers to look inside the structures without ever having stepped a foot in them.
Archaeologists previously tunnelled into the bedrock of the Pyramid of the Sun, at first believing what they had found was a natural cave, but quickly realised they had found an intricate system of tunnels.
Secret tunnels and passages have since been found in other pyramids, including the Temple of Quetzalcoatl, also known as the Feathered Serpent pyramid, in the Aztec city of Teotihuacan.
Discovered by archaeologist Sergio Gómez in 2017, his work since has turned up countless ancient artefacts and the more gruesome discovery of human remains.
His work was captured in a Discovery UK documentary, in which the narrator noted: “Within the Feathered Serpent pyramid, inside the central cell, is a dark secret.”
Here, 20 skeletons were found, almost completely intact, carefully arranged in what looked like a symbolic pattern.
These remains were not alone: over 260 bodies were found to be built unto the fabric and foundation of the building.
The narrator noted: “The pyramid is a mass grave.”
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Mr Gómez explained: “We’ve been working very carefully using lots of small tools so that we don’t lose any of the riches that we uncover.”
He came across two ancient pots which had not been touched for at least 1,800 to 2,000 years.
When combined, his team found more than 100,000 objects along the tunnel, describing them as extraordinary objects,” and noted that, “some of them [have] never [been] seen before in any Mexican archaeological exploration”.
The artefacts included a greenstone crocodile teeth, crystals shaped into eyes, as well as sculptures of jaguars.
And, the tunnel itself was something of an artefact.
Lined in iron pyrite, it reacted to any light by shimmering like the night sky, a reaction likely purposefully induced by the Aztecs in order to replicate the stars.
While the Aztecs flourished for hundreds of years, by the early 16th century, their empire started to come undone.
Invaders led by the Spanish conquistador Hernán Cortés overthrew the Aztec Empire by force and captured Tenochtitlan in 1521.
This finally brought to an end Mesoamerica’s last great native civilisation.