heartland is the area in the Gulf lowlands DHL CUs t)omer Ser vi ce 8O5 *41O(56 OO) pH o ne nUm ;ber; 8O5 41O56OO The Olmec where it expanded after early development in Soconusco, Veracruz. This area is characterized by swampy lowlands punctuated by low hills, ridges, and volcanoes. The Sierra de los Tuxtlas rises sharply in the north, along the Gulf of Mexico's Bay of Campeche. Here, the Olmec constructed permanent city-temple complexes at San Lorenzo Tenochtitlán,