If you are going to Mexico City, then a day trip to Teotihuacan is a must – our kids loved the monumental scale and history there. I would suggest going earlier in the day, or later towards sunset, as it is very hot in the middle of the day climbing all the stairs. Imagine having to build those stairs with very little tools – its just fascinating. Takes about an hour from Mexico City.
Few cities in the world have been considered worthy of being inhabited by Gods, who are accustomed to occupying loftier realms than those peopled by mere mortals. Teot ihuacan is such a city, and a thousand years of civilization, which today can still be felt along its wide avenues projecting out towards the cardinal points of the universe, had to pass before this place could be elevated to the ranks of a mythical city. It is a divine yet human city, patterned with streets and dwelling places which bore witness to bustling activity and into which men and goods entered and exited from the Valley of Mexico, Puebla, Tlaxcala, and even from as far south as the Mixteca and Tehuantepec regions.