Sacred places: Caves (Juxtlahuaca and Oxtotitlán), springs, and mountains. Sites: El Manati, Takalik Abaj, Pijijiapan.
Human Sacrifice: Children and infants at El Manati; human remains under monuments at San Lorenzo; La Venta has an altar showing an eagle-clad king holding a captive.
Bloodletting, ritual cutting of part of the body to allow bleeding for sacrifice, was probably also practiced.
Colossal Heads: Appear to be portraits of male (and possibly female) Olmec rulers. Sometimes wear helmets indicating that they are ballplayers, figurines and sculpture from La Venta show that women wore helmet headgear, and some of the heads may represent women. A relief at the Pijijiapan as well as La Venta Stela 5 and La Venta Offering 4 show women standing next to men rulers, perhaps as partners.
Olmec Trade, Exchange, and Communications
Exchange: Exotic materials were brought in or traded from far places to the Olmec zones, including literally tons of volcanic basalt to San Lorenzo from the Tuxtla mountains, 60 km away, which was carved into royal sculptures and manos and metates, natural basalt columns from Roca Partida.
Greenstone (jadeite, serpentine, schist, gneiss, green quartz), played a clearly important role in elite contexts at Olmec sites. Some sources for these materials are the gulf coastal region in Motagua Valley, Guatemala, 1000 km away from the Olmec heartland. These materials were carved into beads and animal effigies.
Writing: The earliest Olmec writing began with glyphs representing calendrical events, and eventually evolved into logographs, line drawings for single ideas. The earliest proto-glyph so far is an Early Formative greenstone carving of a footprint from El Manati. The same sign shows up on a Middle Formative monument 13 at La Venta next to a striding figure. The Cascajal block shows many early glyph forms.
The Olmec designed a printing press of sorts, a roller stamp or cylinder seal, which could be inked and rolled onto human skin, paper, or cloth.
Calendar: 260 day, 13 numbers and 20 named days.