Junín is a region in the central highlands and westernmost Amazonia of Peru. Its capital is Huancayo.
The region has a very heterogeneous topography. The western cordillera located near the border with the Lima Region, has snowy and ice covered peaks. On the east, there are high glacier valleys which end up in high plateaus (Altiplano). Among them is the Junín Plateau that is located between the cities of La Oroya and Cerro de Pasco.
The Mantaro Valley becomes wider before Jauja up to the limit with the Huancavelica Region. This area concentrates a large share of the region's population. Towards the east, near the jungle, there is an abundance of narrow and deep canyons, with highly inclined hillsides, covered by woods under low-lying clouds.