The Olmec culture, in the area of what is now Veracruz and Tabasco, came into its own in about 1500 B.C.E. The Olmec became powerful and built what seem to have been the earliest of the Mesoamerican pyramids. Their stone sculptures, of which large heads may be seen today, are imposing. The Olmec had a writing system by 300 B.C.E. and a calendar and a great interest in astronomy. Their gods included the ubiquitous Feathered Serpent and other deities who are clearly the mythological ancestors of the deities we find in the later cultures of Monte Alban, Teotihucuan, the Toltec, and the Aztec. By 600 B.C.E., the Olmecs had lost much of their power, and by 300 B.C.E., the culture was essentially extinct.