The ceremonial heart, on the exact centre of the Aztec empire. Go early.
The Zocalo is one of the largest city squares on earth — the ceremonial heart of Mexico City, ringed by the cathedral, the National Palace and the ruins of the Aztec Templo Mayor. Everything radiates from here.
Yes — the historic heart, and the doorway to the cathedral, murals and Templo Mayor; go early.
Yes — it's free to enter.
Come early morning, before the square fills and the sun is high, for the flag-raising, the space and the light.