Apurímac River
The Apurímac River rises from glacial meltwater of the ridge of the Mismi, a mountain in the Arequipa Province in the south-western mountain ranges of Peru, from the village Caylloma, and less than from the Pacific coast. It has been considered the most distant source of the Amazon River. It flows generally northwest past Cusco in narrow gorges with depths of up to, almost twice as deep as the Grand Canyon, its course interrupted by falls and rapids. Of the six attempts to travel the full length of the Apurímac so far, only two have been successful.
After, the Apurímac joins the Mantaro River and becomes the Ene River, above sea level; then after joining the Perené River at above sea level, it becomes the Tambo River; when it joins the Urubamba at above sea level the river becomes the Ucayali, which is the main headstream of the Amazon. Sometimes the complete river from its source to its junction with the Ucayali, including the rivers Ene and Tambo, is called "Apurímac", with a total length of.
In the 13th century, the Inca constructed a bridge over this river which gave them access to the west. Erected around 1350, the bridge was still in use in 1864, and dilapidated but still hanging in 1890. It was the basis for the titular bridge in Thornton Wilder's 1927 novel The Bridge of San Luis Rey. One such bridge, Queshuachaca, is reassembled on an annual basis.