It is situated in the department of Lima, province of Huara over an area of 5070 hectares. The Lomas or Hills are the result of a combination of coastal climate factors and are subject to a peculiar geography. They originate at the exact point where the primary spurring of the Andes contacts the clouds which cover the area most of the year. There are two distinct seasons in Lachay: the humid season - which is the most important - from approximately June to November; and the dry season, from December to May. Typically, during the first season the vegetation becomes green again and attracts the fauna of the region; during the second season, instead, there is a drying process which ends when the first fog appears in the fall.