Chacamarca Historic Sanctuary is located in the southern Junín high plateau, between the central and western mountain ranges in the department, province, and district of Junín. It is at 4,100 m altitude and its 2,500 hectares lie between 11º11´37´´ to 11º14´00´´ southern latitude and 75º56´13´´ to 76º00´00´´ western longitude.
Located in Junín's high plateau, its topography is 65% slightly rolling plains. The remaining 35% is hilly, predominantly in the northwestern sector (Chacamaca Hill) and in its extreme western sector where the eastern flank of Junín Hill is located.
Residual soils are relatively shallow and have clay-like texture. Internal layers are formed of gravel and sand and the surface is made up of an organic layer that decomposes very slowly because of climatic conditions. Pastures and bofedales, which are mostly used for grazing, cover soils.
The area's climate is sub-humid and semi-frigid characterized by lack of rain during winter and fall and lack of well-defined winter thermal changes. This climatic variation is present between 4,100 and 4,800 m where average annual temperatures are 4.8ºC, ranging between 6.0ºC and -3.0ºC. There are two distinct seasons: the rainy season with intense rains that occurs between October and April and the dry season between May and September. Annual average rainfall is 800 mm, varying between 750 and 850 mm.
Añaspuquio is found within the protected area, where Ushno River begins and acts as part of the area's northern border. The Inca Trail passes near the spring and the Challac River that begin in the extreme north of Chacamarca Hill. The Chacamarca and Challac Rivers join together to form Chacachimpa River that flows into Junín Lake (also known as Chinchaycocha). The rivers and streams maintain uniform flow throughout the years and stay calm since they flow through flat topography. Abundant phytoplankton are found in their crystalline waters because they are contaminated with organic waste. Yaropuquio's spring is also found here; its waters formed Chacamarca's old swamp.
Headwaters of three important regional rivers begin in the sanctuary
Chacamarca Historic Sanctuary is located along the central highway, at km 222. To reach the sanctuary from Lima, head towards Oroya then follow a turn-off to Cerro de Pasco. The trip lasts 6 to 7 hours.