This paper concerns the regions of Central and Southern Mexico, Guatemala, British Honduras, and the western parts of Honduras and El Salvador, which are recognized by archaeologists to have constituted a cultural unity in pre-Spanish times. This area was one of the two centres of civilization in pre-Columbian America, Peru, being the other. It includes the several cultural centres north of Tehuantepec, usually grouped together under the name of Mexican Civilization, and those south of that isthmus, in the Mayan zone. For a long time before the Spanish conquest this entire region formed a definite cultural unit—it was a culture area, using this term in the precise meaning as defined by Kroeber—for which the name Mesoamerica is now generally used.