The Aztec great temple, found by electricity workers in 1978 under the corner of the Zócalo, excavated and left open.
On 21 February 1978, electricity workers digging at the corner of the Zócalo struck a carved stone disc more than three metres across.
It was Coyolxauhqui — the moon goddess, shown dismembered, exactly as the myth describes her being killed by her brother Huitzilopochtli at the foot of a mountain.
That told the archaeologists precisely where they were: at the base of the Templo Mayor, the great temple of Tenochtitlan, which had been assumed lost under the colonial city.
The excavation
Buildings on the site were demolished and a full excavation ran from 1978 to 1982, with work continuing since — the Tlaltecuhtli monolith, a twelve-tonne earth goddess, was found in 2006, and excavation is ongoing.
The temple was rebuilt seven times, each phase encasing the last, so what survives is a stack of concentric pyramids with the earliest at the core. That is why the site reads as a maze of platforms and stairways.
It had twin shrines at the top — Huitzilopochtli, war and the sun, and Tlaloc, rain and agriculture — reached by two parallel staircases.
The Spanish demolished it in 1521 and used the stone for the cathedral.
The site
A raised walkway runs over the excavation, which sits several metres below modern street level. You see the successive platforms, the serpent heads, the chacmool figures, and the remains of the surrounding precinct buildings.
It is open to the sky and there is little shade.
The museum
Eight halls, built beside the site in 1987 by Pedro Ramírez Vázquez.
The Coyolxauhqui stone is the centrepiece, displayed at the level it was found. The Tlaltecuhtli monolith, still bearing much of its original red, ochre and blue paint, is in its own hall.
Around 7,000 objects from the offerings buried in the temple — jade, obsidian, coral, jaguar skeletons, sacrificial knives, objects sent as tribute from across the empire, and a substantial number of human remains including the tzompantli, the skull rack, of which a section has been excavated nearby.
The museum does not soften the human sacrifice. It explains what was done, at what scale as far as the evidence allows, and within what cosmology.
Practicalities
Ticketed and inexpensive; free for Mexicans and residents on Sundays. Closed Mondays.
Allow three hours for site and museum together.
The Zócalo metro exit puts you at the entrance.
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