The Olmecs or Olmec were an early major Mesoamerican civilization, flourishing in the modern-day Mexican states of Veracruz and Tabasco from roughly 1200 to 400 BC during Mesoamerica's formative period. They were initially centered at the site of their development in San Lorenzo Tenochtitlán, but moved to La Venta in the 10th century BC following the decline of San Lorenzo. By about 400 BC the major centres of the Olmec civilization had been abandoned, and the population of the eastern half of the Olmec heartland dropped precipitously. The settlement density in that area remained much lower than during the height of Olmec dominance, and only intermittent occupation is evident until much later. Although the Olmec cultural style waned, elements of their tradition lived on in successor societies.