The Huaura is one of the Peruvian rivers flowing down from the west slopes of the Andes into the Pacific Ocean. The river is 120 km long. It originates from the mountain glaciers, over 5000 m a.s.l., in the main Andes ridge, called in those parts the Cordillera Huayhuash, with summits often exceeding 6000 m. The morphology of the area where the archeological investigations took place is varied. Its surface extends at 2300 m to over 5000 m a.s.l. The rivers in their upper run (over 4000 m a.s.l.) flow along U-shaped valleys of glacier origin, with flat bottoms and nearly perpendicular slants. In their lower course intense erosion made those valleys into V-shaped ones. The difference of altitude between the dale bottom and the nearby summits often amounts to 2000 m. The ridges and summits arc narrow, rocky, with precipitous slopes. A characteristic feature of the landscape consists in large screes and taluses.

The climate changes with the altitude. In the uppermost areas, over 4000 m a.s.l., the climate is conspicuously cold, in the region of the lofty glacier summits it becomes typically Alpine. Night and day temperatures differ to a very large extent, and frequently drop below 0°C, especially at night. There are distinctly two seasons: the rainy season from October till April, and the dry season from May till September. During the rainy season it not only rains, frequently it snows and it hails. The dry season is almost completely rainless. The only vegetation in those almost uninhabited regions is grass, moss, and some small species of cactuses. The best part of the contemporary habitat is located between 4000 m down to 2300 m a.s.l., which is the limit of barren desert mountains. The region 4000-2300 m has a moderate climate with regular rainfalls. The vegetation is richer, numerous xerophytes occur, shrubs and small coppices of eucalypti, brought there after the Conquest.

The landmarks of the area under investigation are two towns in the Huaura valley - Churin in its lower and Quichas in its upper course. As far as administration is concerned, the region in question is situated in the department of Lima, the province of Cajatambo, and in the districts of Oyón, Andajes and Pachangara (Fig. 1). I carried out my archaeological investigations - surface investigations only- in those parts on the turn of 1972.