The Putumayo River (Spanish: Río Putumayo, Portuguese: Río Içá) is one of the tributaries of the Amazon River, west of and parallel to the Japurá River. It forms part of Colombia's border with Ecuador, as well as most of the frontier with Peru. Known as the Putumayo in the former three nations, it is called the Içá when it crosses into Brazil. The Putumayo originates from an altitude of 8,000 metres (26,000 ft) in the Andes Mountains east of the municipality of Pasto, Colombia. It empties into the Amazon River near the municipality of Santo Antônio do Içá, Brazil.