Kapuas River

The Kapuas River ( _id. Sungai Kapuas) is located in West Kalimantan, Indonesia. At approximately 1,143 km, it is the longest river in Indonesia, and is the major river of the western portion of Borneo. It is also the world's longest river on an island.

The river rises in the mountains of Kapuas Hulu near the border with Sarawak, Malaysia, and flows west. It empties into the South China Sea about 20 km south of the city of Pontianak. The river drains the extensive Lake Sentarum area, an extensive protected reserve of wetlands and freshwater lakes, and intermittently flooded forests.

Navigable over most of its length, the river is an essential transportation corridor in West Kalimantan. It is used for transportation of timber out of the island's interior, and for access to settlements along the river. The river has one bridge across it, near Sanggau approximately four hundred kilometers from its mouth.