The National Reserve of Junin was established on August 7, 1974 through (D.S.) N 0750-74-AG, It is located in the Pampa of Junin or plateau of Bombom, above 4100 m.a.s.l. and has a surface of 53,000 hectares; in the departments of Junin (districts of Carhuamoyo, Ondores, Junin) province of Junin and Pasco (districts of Ninacaca and Vicco in the province of Cerro de Pasco).

The lake Junin includes the biggest area of the reserve. This lake has a big and rich diversity birds; the zambullidor de Junin (Podiceps Takzanowskii) one of the most important species in the lake that is in danger of extinction. There are other 36 species such as: the pato sutro (Anas flavirustris), the pato jergo (Anas georgica), the pato puna (Anas puna), the huachua (Chloephago melanoptero), the heron (Bubulcus ibis), the pollo de agua (Gallinula chloropus), the seagull (Larus serranus), the huaco (Nycticorax), the Flamingo (Phoenicopterus chilensis), the yanavico (Plegadis ridgwayi) and the zambullidor (Pudiceps occidpitalis).

The only mammal living in the reserve is the wild guinea-pig. The lake Junín is known by its ranas (Frogs) such as: Gastrotheca peruana and Pleurodema marmorata, as well as the toad (Bufo spinulosus). With regard to the fishes we have: Orestias elegans and O. empyraeus, called challhua and a Kind of catfish (Tcichomyeterus oroyae).

The vegetation in the like is very rich, for example the crespillo (Calamagrostis sp.), the Festuca sp. and Stupa brachyphyla, Known as ichu, there are lots of reed plants (Juncus andicola). The main purpose of the reserve is the conservation of the flora and fauna and the lake Junín.