The ancient city of Teotihuacan was the capital of an empire that lasted from 200bc to 550ad. The city reached its peak in 450ad, when it was the center of a powerful culture whose influence extended through much of the Mesoamerican region. It had already been abandoned at the time of the Aztecs, who gave the current name to the city meaning "birth place of the gods". Teotihuacan is located some 40km north east of what is now Mexico City.
Read more on the (Wiki link) and view the site map here or another one here.

Stonework in the morter indicates site reconstruction

Painted images used as writing invented by the Mayans
Palace of the Jaguars
Temple of Quetzalcoatl
The Site Museum

Me on the Pyramid of the Moon looking down the Avenue of the Dead towards the Pyramid of the Sun