Beyond the Basilica is the turnoff to the pyramids of Teotihuacán, 31 miles northeast of Mexico City. The site is one of Mexico's most popular tourist attractions and its first true city. The pyramids of the Sun and Moon, the Ciudadela, or Citadel, with its Temple of Quetzalcoatl (the Plumed Serpent) and the Palace of Quetzalpapalotl (Plumed Butterfly) are the major constructions along the site's nearly mile-long Avenue of the Dead.

The Pyramid of the Sun is the largest, standing 210 feet high. The Teotihuacan monuments were built as flat-topped bases for ceremonial temples reaching high into the sky, to be near the gods.

Archaeologists have discovered a tomb and offerings under the Pyramid of the Moon at the Teotihuacan ruins north of Mexico City. Researchers hope this outstanding find, which includes jade and obsidian figurines, will shed light on the mysterious civilization that flourished here between 150 and 450 A.D., especially its government and ruling class. In this latest phase of explorations, which have continued nonstop since the late 1920s, researchers were tunneling beneath the yramid to study its building patterns. More discoveries are expected.

The site's main drag is the famous Avenue of the Dead, a monumental 2km (1.2mi) thoroughfare lined with the former palaces of Teotihuacán's elite. To its south is the pyramid-bedecked La Ciudadela, believed to have been  the residence of the city's supreme ruler. Enclosed within the citadel's walls is the Quetzalcoatl Temple, with its striking serpent carvings. Heading north, the avenue passes the world's third-largest pyramid: the awe-inspiring,  70m (230ft), 248-stepped Pyramid of the Sun. The pyramid was originally painted a suitably sun-drenched, bloody red.

The avenue terminates at the Pyramid of the Moon, flanked by the 12 temple platforms of the Plaza de  la Luna. Nearby are the beautifully frescoed Palace of the Quetzal  Butterfly, the Jaguar Palace and the Temple of the Plumed Conch Shells. Teotihuacán's most famous mural, the Paradise of Tláloc, is in the Tepantitla Palace, a priest's residence northeast of the Pyramid of the Sun. The site has a museum to help make sense of it all; bring a hat, water and your walking shoes