La Venta

Older than the Maya

The Olmecs lived along the humid Gulf coast of southern Mexico — modern Veracruz and Tabasco — from about 1 500 BC to 400 BC. Six hundred years before the Classic Maya. More than a thousand before the Aztecs.

Archaeologists call them the "mother culture" of Mesoamerica because the calendar, the ballgame, the stepped pyramid, the practice of bloodletting rituals, the rubber technology, and the distinctive cosmology of jaguar-spirit shamanism all appear first in Olmec sites and are then adopted by every later Mesoamerican society. Their two great centres were San Lorenzo (1 200–900 BC) and La Venta (900–400 BC).

Seventeen heads

Seventeen colossal stone heads have been found. All carved from single blocks of basalt quarried in the Tuxtla Mountains and somehow transported across 80 kilometres of swamp and river to the ceremonial centres.

The largest is 3.4 metres tall and weighs 25 tonnes. Each shows distinct facial features — broad fleshy lips, wide flat nose, slightly almond-shaped eyes, a tight helmet-like headdress with individual decorative bands — and no two are alike. The standard interpretation is that they are portraits of specific rulers. The helmets may be ballgame protective gear or military headdress.

What they are not — despite a recurring fringe theory — are evidence of African contact. The facial proportions and headdress style are demonstrably indigenous Mesoamerican.

How the basalt got there

The basalt boulders came from the Cerro Cintepec quarry in the Tuxtla range, 80 to 120 kilometres from where the heads were finally placed.

There were no draft animals in pre-Columbian Mesoamerica — no horses, no oxen, no donkeys — and no wheels in use beyond children's toys. The transport almost certainly used rafts on the Coatzacoalcos river system during the rainy season, when the swamplands flooded enough to float a 25-tonne stone. Once landed, the boulders were dragged on log rollers by teams of hundreds.

Carving was done with stone tools — the Olmecs had no metal — using harder hematite hammerstones to peck away the basalt and sand abrasives to polish the finished features.

Why La Venta buried itself

Around 400 BC the great Olmec ceremonial centre at La Venta was abandoned. Before leaving, the inhabitants deliberately defaced their own monuments. The colossal heads were toppled. Some had their features hammered off. Others were carefully buried face-down in prepared pits.

Why a civilisation would terminate itself in this way is unknown. Proposed explanations include volcanic disruption, climate change shifting the river systems, internal political collapse, or ritual closure of a sacred place.

The Olmec heartland was overgrown by jungle within a century. When the Aztecs encountered Olmec carvings nine hundred years later they treated them as the relics of a vanished people whose name they did not know.