The Ucayali River (, ) arises about north of Lake Titicaca, in the Arequipa region of Peru. The Amazon River takes its name close to Nauta city (100 km upstream/south of Iquitos), at the confluence of the Marañón and Ucayali rivers. The Ucayali becomes a major tributary of the Amazon River. Navigation was blocked by lengthy sections of rapids. The city of Pucallpa is located on the banks of the Ucayali.