The rivers which have their source in Vilcanota or Cerro de Pasco are no more than little rivulets of melted snow as they first appear in the crevices of the high sierra; but they are fed by a thousand streams along their course, and increase rapidly in volume as they flow toward the plain, following the channel cut for them in the course of ages, now carved so deep that, in some places, it lies at the bottom of a chasm thousands of feet below the level of the bordering hills and plains. It is only after leaving the region of the sierra that these rivers are navigable, though they are capable of supplying unlimited motive power for manufacturing and other purposes. Many of them are famous in history and a few have claims to particular interest through their association with the legends and traditions of the Incas. The Apurimac, across which Maita-Ccapac swung the first American suspension bridge, has its source in the Laguna de Vilafro, fourteen thousand feet above sea level, in the Department of Arequipa. It receives many affluents, and, as it descends into the lower valleys, drains a country rich in agriculture, one of the most productive regions of Peru. It was on the border of this river that General Sucre and his army were encamped by Bolivar’s orders, when the news of the royalist army’s approach led to the rapid change of plans which resulted in General Sucre’s becoming the hero of Ayacucho. To-day, the beautiful valleys of this region blossom with the fruits of peaceful industry, and thriving towns adorn its landscapes. Abancay, the picturesque capital of the Department of Apurimac, is surrounded by sugar plantations, and the _campiña_ is dotted with mulberry trees, the silkworm industry being a profitable source of revenue. The Urubamba River, like the Apurimac, flows through a fertile valley, crossing the Department of Cuzco in a northwesterly course from the border of Puno to the southern limit of Loreto, where it forms a confluence with the Tambo—as the Apurimac is called after receiving its last tributary, the Perené,—and enters the broad channel of the Ucayali. The Urubamba has a number of tributaries, the most important of which is the Paucartambo; along the courses of these rivers are fields of sugar-cane, and in the lower valleys grow cacao and all tropical fruits.