Teotihuacan is an ancient Mesoamerican city located in a sub-valley of the Valley of Mexico, which is located in the State of Mexico, 40 kilometers northeast of modern-day Mexico City. Teotihuacan is known today as the site of many of the most architecturally significant Mesoamerican pyramids built in the pre-Columbian Americas, namely the Pyramid of the Sun and the Pyramid of the Moon.