The small Museo de Tres Zapotes notably has the 1.5m Tres Zapotes head, an Olmec head dating from about 100 BC. The biggest piece, Stela A, depicts three human figures in the mouth of a jaguar. Other pieces include a sculpture of what may have been a captive with hands tied behind his back and the upturned face of a woman carved into a throne or altar. The museum attendant is happy to answer questions in Spanish or give a tour (tipping is appreciated).
