Memorial del 68

To the south, you'll see the modern-day tower and its adjacent buildings, which were built for the Secretary of External Relations (SRE), now headquartered across the street (though they still have offices in the church's adjoining cloister). UNAM runs the building as a conference hall and cultural center, and has a few exhibits open to the public: Memorial 68 (see Museums, below) and the Blaisten Collection, showcasing modern art.

The colonial church, built by Spaniards immediately after destroying the temple in their conquest of Aztec lands, was constructed using stones "borrowed" from the temple itself. Despite its weathered appearance, the interior is well-maintained and should still hold regular Mass, although doors may not always be open to the public.

The temple, like Tenochtitlan's Templo Mayor, was built in several layers and is now the site of continuing archaeological exploration; it occupies the largest amount of area, on the north and west side of the plaza. If you're not around for the tour, you can guide yourself along the path (complete with English plaques) that takes you through the ruins, which deposits you in front of the Church of Santiago, on the east side of the plaza.

This museum managed by the Medicine Faculty of the National University shows the history of health care in Mexico. Features a great replica of an old pharmacy and reconstructed labs of influential medical researchers. Signage is in Spanish only. It is housed in the Inquisition Palace, built between 1732 and 1737, which was the head office of the Holy Inquisition, the religious authority famous for torturing heretic people.

The second largest square in Centro Histórico after the Zócalo. It is surrounded by various important buildings such as the Palacio de la Inquisición, Santo Domingo convent and the old Customs House.

Architecturally unique and utterly fascinating restored neoclassical mansion from the Porfiriato era of the 19th century with period furnishings. Guided tours (in Spanish).