Driving from Mexico City take the road that goes to "Toluca" which is going west. You can take the toll road but I don't because it doesn't save much time at all (if you are already on the west side of the city). Once you leave Mexico City not too far you will reach a popular outdoor area called "La Marqueza", stick to the right and take the road that goes to the small city of "Salazar". It crosses a railroad track just inside the town. Stay on that main road and continue to go north 1.0 mile (from the railroad track in Salazar) and your will reach a "Y", turn right and stay on for another 0.4 mile. You will see a dirt road on the right side, make a sharp right on that road and go like 500 feet and on the left you will see a private one lane concrete drive up a really steep hill. Go up the hill and you will see a house, the property owner has a couple dogs that mostly bark but act like they want to eat you. (I'm thinking that's why it's called Los Perros). The GPS address is approximate but close enough to find. See video below: facebook.com/photo.php?v=15603...
The property owner charges a small fee for parking and climbing and is subject to change (probably if they hear you have an accent ;-)
Several beginner climbs and intermediate from 5.8 to 5.11b sport routes, 10 routes in total. It's a popular area so expect people on weekends. You can also walk to the top if you want to set up top rope.
Climbing is year-round except when it rains (very frequent during summer). Another distinguishing note is it's generally a safer area than many other areas around Mexico City. The homeowners where you park the car watches your car and suspicious activity. I haven't heard of any robberies based on several conversations from the locals. (Be aware of other areas where robberies are common - this is why I went to this place vs other areas around the city).
Fore more information on climbing areas in Mexico visit escalando.net
Climbing Season For the Mexico area.
Weather station 2.3 miles from here
Featured Route For Los Perros