Lake Petén Itzá, Lake in Petén Department, Guatemala

Lake Petén Itzá is a freshwater lake in Guatemala's northern Petén Department, the country's third largest, covering 99 km², about 32 km long and 5 km wide, with a maximum depth of 160 m. The city of Flores, capital of Petén, lies on an island near its southern shore. The lake has no surface outflow and loses water mainly by evaporation, yet it is not a salt lake.

Lake Petén Itzá holds the archaeological remains of Tayasal, the Itza Maya capital, on a peninsula near the former Itza capital; it was the last Maya city conquered in Mesoamerica, in 1697. At least 27 Maya sites ring the lake. The Itzá name derives from itz (wizard or magician) and a' (water), rendered as "wizard of the water" by Alfredo Barrera Vásquez.

The name Itzá comes from itz, meaning sorcerer or magician, and a', water, so the lake's name can be read as "water sorcerer"; some authors translate it as "enchanted waters". The Itzá Maya capital stood by the lake until 1697, when the Spanish took it, the last Maya stronghold conquered in Mesoamerica. Around the shore lie at least 27 Maya sites, including Tayasal.

The town of Flores on the island is the main base for exploring the lake and staying overnight. The climate is tropical and humid, so light clothing and insect protection are practical considerations.

A protected forest area on the northeast shore is home to toucans, spider monkeys, and rare butterflies that live in the tree canopy. This reserve shows the diversity of tropical life surrounding the water.