Templo Mayor is a pyramid in Mexico, main Temple of Tenochtitlan. Pyramason catalogues it as PYR-066027 at 19.43500, -99.13139 (19°26'06.0"N 99°07'53.0"W).
Wikidata records a construction date of about 1325 CE.
There are 17 other catalogued sites within 5 km of it, 47 within 25 km and 67 within 50 km. That density is itself the finding: this is not an isolated monument but part of a worked landscape.