Planning Your Time
You could spend weeks in Mexico City—there are enough museums, restaurants, and side trips to keep even the most jaded globe-trotter occupied for a long time—but how much time you spend in the capital really depends on your expectations and your tolerance for fast-paced urban living. If you're short on time and anxious to move on to friendlier (or more scenic) climes, you can see a lot in two days, though three would be ideal.
With three days you'll have enough time to tour the historic sights, do a little museum-hopping, have more than a few fabulous meals, and spend at least part of one day on a side trip to nearby ruins. Hard-core city travelers will want to spend a week here to feel like they've really covered enough ground.