Istmina is a municipality and town in the Chocó Department, Colombia. The town of Istmina was founded in 1834 by Juan Nepomuceno Mosquera, initially with the name of San Pablo. The name was changed in 1903 to Istmina, a contraction of isthmus and minas (mines), two characteristics of the area. The municipality covers 2,480 square kilometres (958 sq mi), with an average elevation of 79 metres (259 ft), and an average temperature of 25.9 °C (79 °F).