The Maya civilization was a Mesoamerican civilization developed by the Maya peoples, and noted for its hieroglyphic script—the only known fully developed writing system of the pre-Columbian Americas—as well as for its art, architecture, mathematics, and astronomical system. The Maya civilization developed in an area that encompasses southeastern Mexico, all of Guatemala and Belize, and the western portions of Honduras and El Salvador. This region consists of the northern lowlands encompassing the Yucatán Peninsula, and the highlands of the Sierra Madre, running from the Mexican state of Chiapas, across southern Guatemala and onwards into El Salvador, and the southern lowlands of the Pacific littoral plain.