The ancestors of the people we know today as the Zapotecs built the first real city in Mesoamerica on the flat top of Monte Alban, the ruins of which are spectacularly accessible near present-day city of Oaxaca. The Monte Alban civilization gradually became the major southern Mexican power for some thousand years, beginning in about 600 B.C.E. As did the Olmec, the Teotihuacan people, and the Maya, the Zapotec built pyramids, had calendar and writing systems, and had an interest in astronomy. They worshipped a number of gods who seem to be related to those of the other early Mesoamerican cultures, including the Feathered Serpent, associated with the god/hero Quetzalcoatl.