other olmec sis hapushed back the ginning of olmec culture by more than a milleium, to circa 1,200 b.c. newsre announcer: now we're off for the second phase of our exploration. obregon: stirling beganigging at san lorenzo in 1946, with the archaeologist philip dcker. stirling pugh: and sure enough, ere was a big head, a beautifully carved big head, much finer [d] more ndsome thanhe ones at la venta. regon: stirling proposed that these enigmatic sculptures wereortraits of prominent individuals in olmec society. mostf the vast site of san lorenzo remains to be explored. new speaker: we now know athe site cove moran 300 hectares, making it the laest and most complex site in mesoamerica duri t earressic orhearlyormati period. obregon: the elite resided on the huge manmade plateau that dominates the site. one house, calle the "red palace," had stone columns and steps and was supplied with war channeled fromeservoirs. ordinary pple may have led in the pthatched houses, like some still found ere toy. the population included artisans skilled in specializedrafts. cyphers: we have a lot of evidence for