Okay, this is less a trip report than an average day in what might be among the world's top 5 urban crags (I'd actually be really curious to see that list). Get up in the morning at 7 or so and hop on either the Metro or the Metrobus and get to Perisur in the south of the city. Buy some tamales for the road if you dare or a tamale sandwich - a tamale wrapped in bread that hits your gut with a thump. Catch a cab for US$10 to Dinamos National Park. On the way, you will pass adorable little towns that used to be independent of DF and still feel like something out of a movie. Stop and grab coffee at one of the town squares if you like.
If you want to clip bolts or just eat tacos all day, stop at the 2nd Dinamo (an old dam generator in the river). But if you want some of the best basalt cracks this side of the Pecos keep going to the 4th Dinamo or "Coconetla" in the old Aztec. You will notice that you are totally free of the city and will suck in the crisp air and pines at 10,00 feet. Don't worry, you are still technically in Mexico City!
Skip the food here - it's too pricey and not great. Go straight to the massive wall hanging over the valley to your right. Long winding trail will get you there - probably. At the base, you will find the jolliest crew of misfits and hardmen south of the Rio Grande. Routes run from 5.8 to hard 5.11 and most are three very vertical pitches or so. Do Viaje Mágico y Misterioso. three of the coolest pitches this side of ... I don't know .. the Colorado River? Every route here is clean climbing, totally vertical, and just stunning. And the views are next to none. Dalias, Hormigas, and Marlon Brandon are not to be missed!
After you are good and tuckered out, hitch a ride down to Hongos, a taco place halfway down the road to 2nd Dinamos. Oh my God, no stuff you starving little face with the greatest rabbit tacos this side of ... anywhere. Continue down the the mountain and ponder why it is that you have never heard of this amazing place before now.