The Marañon, and its tributary, the Huallaga, flowing northward from the Nudo of Cerro de Pasco, water a region of surpassing fertility, in the valleys of which are to be seen every variety of agricultural product. The Marañon receives a great many tributaries from the Occidental range as it flows northward across the Department of Huánuco, turning northwest between Loreto and Ancash, and traversing the Department of La Libertad. After dividing the Departments of Cajamarca and Amazonas for some distance, it makes a curve to the northeast and, turning sharply in an easterly direction, pursues a tortuous course until joined by the Ucayali, to form the Amazon. In changing its direction from northwest to east, the Marañon passes the “pongo,” or falls, of Manserriche, the last and most important of a series of rapids which mark an effort to free its current from the confining Andes. From the north, the Marañon receives the Santiago, Morona, Pastaza, Tigre, and other tributaries, while from the south, its chief affluent is the Huallaga. The greatest variety of scenery and climate marks its course, which begins on the high _puna_, in the midst of snowy peaks, and descends between mountain slopes, on which cattle and sheep graze in perennial pastures, through valleys dotted with orchards, and fertile levels where cotton, tobacco, and sugar-cane grow, to the region of the Montaña, fruitful in cacao, coca, and other products of a tropical zone. In the valleys drained by the tributaries of the Marañon are situated some of the most prosperous farms and plantations of Peru, though the wealth of this region has never been exploited on a scale of sufficient importance to show what it is capable of producing. Cajamarca, the capital of the Department of the same name, and Chachapoyas, the capital of the Department of Amazonas, are the most important industrial centres of this inter-Andean valley. [Illustration: NATIVE BOATMEN ON LAKE TITICACA.] Cajamarca, the historic city of the Conquest, celebrated as the site of the capture and execution of Atahuallpa, lies in an oval plain surrounded by mountains and traversed by the Camarca River, a branch of the Marañon. Interesting ruins remain to give an idea of the great structures built by the Incas or their predecessors, and the hot springs are as efficacious to-day as they were when the last unhappy monarch of Cuzco found them a source of royal comfort and pleasure. The valley of Cajamarca is well cultivated, the inhabitants being industrious and thrifty.