Everybody says Mexico City is an extremly dangerous city, but from my experience I can tell you, that as long as you don't run around in expensive clothes and shoes without any jewelry, noboy will do you any harm. Actually it's the opposite: Mexicans are warm hearted people how are very proud of their country, and especially of Mexico City, and like to share their knowledge of it with everybody!

Very important to see, besides the usual things you can read in every guide, are the different markets in different parts of the town (especially the "TEPITO" market. Also very interesting are the little Taco Bars in the streets. Don't think about what to eat. Just eat and then ask!