added by archaeologs The oldest-known Olmec center, located in Veracruz, Mexico, and revealing information on Olmec origins. It was a large nucleated village flourishing during the Early Formative. The first phase of occupation (Ojochi, c 1800-1650 BC) left no architectural traces, but during the next period (Bajío, 1650-1550 BC) a start was made on the artificial plateau with lateral ridges forming the base of most subsequent structures. The Chicharras phase (1550-1450 BC) foreshadows true Olmec in its pottery, figurines, and perhaps also in stone-carving. The San Lorenzo phase (1450-1100 BC) marks the Olmec climax at the site, whose layout then resembled that of La Venta. The principal features of the site are a large platform mound and a cluster of smaller mounds surrounding what may be the earliest ball court in Mesoamerica; more than 200 house mounds are clustered around these central features. A system of carved stone drains underlying the site is a unique structural feature. Around 900 BC, the stone monuments were mutilated and buried upon the center's collapse. La Venta then came to power. The monuments weighed as much as 44 tons and were carved from basalt from the Cerro Cintepec, a volcanic flow in the Tuxtla Mountains about 50 air miles to the northwest. It is believed that the stones were somehow dragged down to the nearest navigable stream and from there transported on rafts up the Coatzacoalcos River to the San Lorenzo area. The amount of labor involved must have been enormous, indicating a complex social system to ensure the task's completion. Most striking are the colossal heads human portraits on a stupendous scale, the largest of which is 9 feet high. After a short hiatus, the site was reoccupied by a group whose culture still shows late Olmec affinities (Palangana phase, 800-450 BC), but was again abandoned until 900 AD when it was settled by early post-Classic (Villa Alta) people who used plumbate and fine orange pottery. The collapse of San Lorenzo c 1150/1100 BC was abrupt and violent. The population was forced to do its agricultural work well outside the site, which may have contributed to the center's collapse.