Limpopo, river in southeastern Africa, rising as the Krokodil River in the mountainous Witwatersrand region of northern South Africa. The Krokodil flows northwest until it joins the Marico River at the Botswana border. It then becomes the Limpopo and continues northeast along the border between Botswana and South Africa, then east along the border between Zimbabwe and South Africa. It flows southeast through southern Mozambique before entering the Indian Ocean near Xai-Xai. The river is 1,800 km (1,100 mi) long and is navigable for 210 km (130 mi) from the mouth. Irrigation projects have been built on it in South Africa and Mozambique.