The national university (UNAM) is located on a sprawling campus in the south of the city, and worth a full day's trip down to explore the area. The campus is also known as Ciudad Universitaria, and it is indeed so big that it is like its own city. Hit a Pumas soccer game in the Olympic stadium, check out the monumental murals by Juan O'Gorman and David Siqueiros, enjoy Modernist Mexican architecture in its full splendor, discover the hidden Sebastián, Manuel Felguérez, and Mathias Goeritz sculptures in the overgrown sculpture garden, and then catch the latest exhibition at the awesome Museum of Contemporary Art (MUAC). In short, there's a lot to do.
Museo Casa Estudio Diego Rivera y Frida Kahlo
Av. Altavista esq. Diego Rivera, San Angel
This is one of the main stops on the Diego Rivera and Frida Kahlo pilgrimage, as they lived in this home on and off for twenty years. Their muralist friend Juan O'Gorman designed the now iconic house specifically for them, with separate buildings for each, united by a drawbridge between the two (they notoriously needed a lot of space from one another). It's a quick stop that's mostly worth it for the architecture, with a small temporary exhibition space, a few rooms dedicated to both artists, and Diego's studio, where he made many of his most famous paintings surrounded by floor-to-ceiling windows and huge paper maché Judas sculptures.
El Bazaar Sábado
San Jacinto 11, San Ángel
On Saturdays, as the name implies, one of the most delightful things you can do is head over to the sleepy, cobble-stoned streets of San Angel to shop in this grand old colonial plaza. It's jam-packed with artists and artisans who sell their wares here week after week, including paper flowers, embroidered blouses, tin toys, carved Pepita glass, etc. Some of it is on the folksy side, but there's always at least one discovery to walk away with. Plus, there's a restaurant inside serving solid quesadillas (though there's also a street stand right outside that out-does these), and right across the street is the weekly artist's street market, where there are some good finds to be made.