The Olmec colossal heads are at least seventeen monumental stone representations of human heads sculpted from large basalt boulders. The heads are a distinctive feature of the Olmec civilization of ancient Mesoamerica. All portray mature men with fleshy cheeks, flat noses, and slightly crossed eyes; their physical characteristics correspond to a type that is still common among the inhabitants of Tabasco and Veracruz. The backs of the monuments often are flat. The boulders were brought from the Sierra de los Tuxtlas mountains of Veracruz. Given that the extremely large slabs of stone used in their production were transported over large distances, requiring a great deal of human effort and resources, it is thought that the monuments represent portraits of powerful individual Olmec rulers. Each of the known examples has a distinctive headdress. The heads were variously arranged in lines or groups at major Olmec centres, but the method and logistics used to transport the stone to these sites remain unclear.
Dating the monuments remains difficult because of the movement of many from their original contexts prior to archaeological investigation. Most have been dated to the Early Preclassic period (1500–1000 BC) with some to the Middle Preclassic (1000–400 BC) period. The smallest weigh 6 tons, while the largest is variously estimated to weigh 40 to 50 tons, although it was abandoned and left unfinished close to the source of its stone.
The Olmec civilization developed in the lowlands of southeastern Mexico between 1500 and 400 BC. The Olmec heartland lies on the Gulf Coast of Mexico within the states of Veracruz and Tabasco, an area measuring approximately 275 kilometres east to west and extending about 100 kilometres inland from the coast. The Olmecs are regarded as the first civilization to develop in Mesoamerica.
The Olmecs were the first inhabitants of the Americas to construct monumental architecture and to settle in towns and cities. They were also the first people in the Americas to develop a sophisticated style of stone sculpture. In the first decade of the 21st century evidence emerged of Olmec writing, with the earliest examples of Olmec hieroglyphs dating to around 650 BC. Examples of script have been found on roller stamps and stone artefacts; the texts are short and have been partially deciphered based on their similarity to other Mesoamerican scripts. The evidence of complex society developing in the Olmec heartland has led to the Olmecs being regarded as the "Mother Culture" of Mesoamerica, although this concept remains controversial.
The seventeen confirmed examples of Olmec colossal heads are known from four sites within the Olmec heartland on the Gulf Coast of Mexico, namely San Lorenzo Tenochtitlán, La Venta, Tres Zapotes, and La Cobata.
La Venta Monument 1 is speculated to have been the portrait of La Venta's final ruler. Monument 1 measures 2.41 metres high by 2.08 metres wide by 1.95 metres deep; it weighs 24 tons. The front of the headdress is decorated with three motifs that apparently represent the claws or fangs of an animal. Above these symbols is an angular U-shaped decoration descending from the scalp. On each side of the monument a strap descends from the headdress, passing in front of the ear. Each ear has a prominent ear ornament that descends from the earlobe to the base of the monument. The features are those of a mature man, with wrinkles around the mouth, eyes and nose. Monument 1 is the best preserved head at La Venta but has suffered from erosion, particularly at the back. The head was first described by Franz Blom and Oliver La Farge who investigated the La Venta remains on behalf of Tulane University in 1925. When discovered it was half-buried; its massive size meant that the discoverers were unable to excavate it completely. Matthew Stirling fully excavated the monument in 1940, after clearing the thick vegetation that had covered it in the intervening years. Monument 1 has been moved to the Parque-Museo La Venta in Villahermosa. The head was found in its original context; associated finds have been radiocarbon dated to between 1000 and 600 BC.