Plaza de las Tres Culturas

This plaza sits on the ruins of Tlatelolco, once home to the largest market in Mesoamérica and the final site where the Aztec empire fell on August 13, 1521. Three layers of architecture define the space: pre-Hispanic pyramids and temple foundations, the colonial-era Templo de Santiago and Colegio de la Santa Cruz (founded 1536 as the first institution of higher education in the Americas), and the modernist Nonoalco-Tlatelolco housing complex designed by Mario Pani in the mid-20th century.

The plaza is also the site of the October 2, 1968 massacre, when military and paramilitary forces opened fire on student protesters. A plaque marks the event with a line from Rosario Castellanos's poem: "No fue triunfo ni derrota. Fue el doloroso nacimiento del pueblo mestizo que es el México de hoy."

Free admission. The archaeological zone is open for walking, and you can enter the Templo de Santiago. Senior citizens enter the archaeological area at no charge. It's a quiet, reflective space better visited after reading a bit about its history — the full weight of the place comes through when you know what happened here.