The most striking feature about San Lorenzo, along with other Gulf Coast Olmec centers, is the number, size and beauty of its monuments. The first artists in Mesoamerica were the Olmec sculptors, and they produced a distinctive style which ranks with any in the world. The monuments all of which were fashioned from basalt brought laboriously form a source in the Tuxtla Mountains, some 80 kilometers north-northwest from San Lorenzo, include eight colossal heads, the largest of which is 2-3 meters high and probably weights over 20 tonnes. It is virtually certain that these heads are portraits of Olmec rulers; their faces, with thickened, everted lip and flat noses, are reminiscent of the physiognomies to be seen in some southeastern Asiatic populations, but each is distinctive, as is the emblematic device on their protective helmets. In fact, these may have been worn in the sacred ballgame which we know from clay figurines to have been played by the Olmec.

Other monuments include “altars,” great tabletop oblongs, the fronts of which show cross-legged rulers seated in niches, each either holding a were-jaguar baby in his arms, or else grasping a cord binding captives taken in war, most likely symbols royal succession and martial prowess. A host of San Lorenzo rulers with the divine pantheon an exceedingly complex series of grotesque supernaturals combining human and animal features, downturned, snarling mouth and infantile anthropomorphism.

Another clearly nonpractical aspect to San Lorenzo, which was surely a ceremonial center in the strictest sense, in the presence of an extraordinary system of stone drains—U-shaped pieces of basalt laid end-to-end and fitted with stone covers. These are believed to have drawn off water from artificial ponds on the surface of the site which were probably used for ritual bathing. Since the Olmec were without metal tools to work stone, the amount of labor involved in producing such a system is staggering.

San Lorenzo might have been a center revered all over Early Formative Mesoamerica for its sanctity; here must have lived the mightiest of Olmec rulers and priests. It is impossible to estimate the population of the entire region, but the presence of about 200 earthen house mounds suggest a figure of about 1000 supporters and retainers within the ceremonial center. Abundant manos and metates indicate the maize agriculture, carried out on the river levees and in the more upland area, was the base of the economy, but preserved faunal remains show that they relied heavily upon the fishing of snook, and the killing of turtles and domestic dogs for their meat supply. They were almost surely cannibals, for the remains of what seems to be slaughtered captives occur in kitchen middens.

The Olmec heartland is singularly deficient in many raw materials which were paradoxically prized by the San Lorenzo elite. Obsidian, for instance, which played a role in Mesoamerica similar to steel in western civilization, is found only in volcanic regions of Mexico and Guatemala far from the heartland. Yet probably several tonnes of this volcanic glass, so useful for cutting instruments, were imported by San Lorenzo from a wide variety of natural sources, as is proved by trace-element analysis. Another much-prized and imported substance was iron ore capable of taking a high polish, for this was turned into parabolic, concave mirrors which must have played a great ritual role. One finely tooled, lodestone silver may well have acted as the world’s first known compass, dedicated to geomantic purposes.