La Venta is a pre-Columbian archaeological site of the Olmec civilization located in the present-day Mexican state of Tabasco. Some of the artifacts have been moved to the museum "Parque - Museo de La Venta", which is in nearby Villahermosa, the capital of Tabasco.
The Olmec was one of the first civilizations to develop in the Americas. Chronologically, the history of the Olmecs can be divided into the Early Formative (1800-900 BCE), Middle Formative (900-400 BCE) and Late Formative (400 BCE-200AD). The Olmecs are known as the "mother culture" of Mesoamerica. "Mother culture" meaning, that the Olmec civilization was the first culture that spread and influenced Mesoamerica. The spread of Olmec culture eventually became the cultural features found throughout all Mesoamerican societies. Rising from the sedentary agriculturalists of the Gulf Lowlands as early as 1600BCE in the Early Formative period, the Olmecs held sway in the Olmec heartland, an area on the southern Gulf of Mexico coastal plain, in Veracruz and Tabasco. Prior to the site of La Venta, the first Olmec site of San Lorenzo dominated the modern day state of Veracruz (1200-900 BCE).
Roughly 200 kilometres (124 mi) long and 80 kilometres (50 mi) wide, with the Coatzalcoalcos River system running through the middle, the heartland is home to the major Olmec sites of La Venta, San Lorenzo Tenochtitlán, Laguna de los Cerros, and Tres Zapotes.
The Olmec Heartland, showing La Venta.
By no later than 1200 BCE, San Lorenzo had emerged as the most prominent Olmec center. While a layer of occupation at La Venta dates to 1200 BCE, La Venta did not reach its apogee until the decline of San Lorenzo, after 900 BCE. After 500 years of pre-eminence, La Venta was all but abandoned by the beginning of the fourth century BCE.
Located on an island in a coastal swamp overlooking the then-active Río Palma, La Venta probably controlled a region between the Mezcalapa and Coatzacoalcos rivers. The site itself is about 16 kilometres (9.9 miles) inland at an elevation of less than 10 meters above sea level with the island consisting of slightly more than 2 square miles (5.2 square kilometres) of dry land, resting on the largest alluvial plane in Mexico. The humid tropical climate of La Venta has an average annual temperature of 26 degrees Celsius and an average annual rainfall of 2,000 millimeters. La Venta is located at the nexus of four different ecosystems: marshes, mangrove swamps, tropical forest, and the Gulf of Mexico.
“There was a large resident population at the site, a number of specialists not dedicated to food production, and political, religious, economic, and/or military relations with other sites within its area of influence.”  Unfortunately, few, if any, of the residential structures surrounding the large centers of the city have survived. The main part of the site is a complex of clay constructions stretched out for 20 kilometres (12 miles) in a north-south direction, although the site is oriented 8° west of north. The urbanized zone may have covered an area as large of 2 km2. This particular site layout is the way the city was from 600 – 400 BCE, which is when the final Olmec occupation occurred. This site is particularly fascinating because of its layout—not only does Complex A face within 8 degrees of true North, but the east and west sides of the sight are almost identical, showing bilateral symmetry. This is perhaps related to religion (it’s fairly speculative, at this point) but it certainly shows a high level of sophistication and city-planning.
Unlike later Maya or Aztec cities, La Venta was built from earth and clay—there was little locally abundant stone for the construction. Large basalt stones were brought in from the Tuxtla Mountains, but these were used nearly exclusively for monuments including the colossal heads, the "altars" (actually thrones), and various stelae. For example, the basalt columns that surround Complex A were quarried from Punta Roca Partida, on the Gulf coast north of the San Andres Tuxtla volcano. “Little more than half of the ancient city survived modern disturbances enough to map accurately.”  Today, the entire southern end of the site is covered by a petroleum refinery and has been largely demolished, making excavations difficult or impossible. Many of the site's monuments are now on display in the archaeological museum and park in the city of Villahermosa, Tabasco.