Shanay-timpishka
The Shanay-timpishka, more popularly known as the "Boiling River of the Amazon", is a tributary of the Pachitea River, which subsequently flows into the Ucayali River, the main headstream of the Amazon River. It is one of the largest documented thermal rivers in the world; the entire river system is around 9 km (5.6 mi), but only the lower 6.3 km (3.9 mi) is thermal.