The municipality of Lloró holds the Highest Average Annual Precipitation record measured at 523.6 inches (13,300 mm) which makes it the wettest place in the world. Three large rivers drain the Chocó Department, the Atrato (which runs north, with tributaries that also flow north), the San Juan, and the Baudó. Each has many tributaries. The Baudó Mountains on the coast and the inland Cordillera Occidental are cut by low valleys, with an altitude less than 1,000 meters, that form most of the territory. Most of the Chocó is thick rainforest. Much of the wood for Colombia's internal consumption is harvested from the Chocó, with a small percentage harvested for export.