Petén is a department of Guatemala. It is geographically the northernmost department of Guatemala, as well as the largest by area – at 35,854 km2 (13,843 sq mi) it accounts for about one third of Guatemala's area. The capital is Flores. The population at the mid-2018 official estimate was 595,548.

The Mirador Basin is a hypothesized geological depression found in the remote rainforest of the northern department of Petén, Guatemala. Mirador Basin consists of two true basins, consisting of shallowly sloping terrain dominated by low-lying swamps called bajos; one draining into the San Pedro River and the other into the Candelaria River. The basin is surrounded by rugged karstic limestone hills on the east and south, forming a triangular geographical "trough" covering more than 2,169 km2 (837 sq mi). The geological formation of the landscape, as well as the significance of the formation, are the subject of some controversy in Northern Guatemala. NASA Shuttle Radar Topography Mission (SRTM) data indicate no depression in the area.