Petén (pātān´), region, c.15,000 sq mi (38,850 sq km), N Guatemala. A humid expanse of dense, tropical hardwood forests interrupted by savannas and crisscrossed by ranges of hills, it is related geographically to SE Mexico and Belize rather than to the rest of Guatemala. The Usumacinta River system drains most of the region. Rainfall is very heavy. There are large, permanent lakes, notably Lake Petén Itzá. The region is relatively inaccessible and has been only partly developed. It produces lumber, chicle, and some rubber and cacao. The sparse population is mostly Native American. Flores is the chief town.
Once Petén was a center of the Old Empire of the Maya and had a dense agricultural population. It is noted chiefly today as the scene of large-scale excavations of great archaeological ruins, notably Tikal and Uaxactún. Although the Spanish nominally conquered the area and Cortés passed through it on his march to Honduras (1524–25), efforts at subjugation were sporadic until the Itzá tribe was driven out (1697) from their stronghold at Lake Petén Itzá.