The Huayllay National Sanctuary is a forest of stones, with impressive cliffs and bizarre figures formed by erosion caused by wind, water and glaciers. The rock forest is a major tourist attraction for both hiking and sightseeing as well as an international destination for rock climbers.
The Huayllay National Sanctuary is a protected area located on the Bombón Plateau in Peru's central Andes (Pasco region) between 4,100 - 4,546 m (13,450 - 14,915 ft) above sea level. The sanctuary is noted for the large scenic rock formations of the rock forest of Huayllay and its native plants and animals.
The sanctuary is a forest of stones, with impressive cliffs and bizarre figures formed by erosion caused by wind, water and glaciers. The rock forest is a major tourist attraction in Peru, for both hiking and sightseeing. It is also an international destination for rock climbers.
The rock formations date to the beginning of the Cenozoic age. They were initially formed when volcanic activity deposited layers of hardened volcanic ash, or ignimbrite on the landscape, forming a plateau atop layers of sandstone, limestone, and conglomerate. Ignimbrite is a porous rock, so it is particularly vulnerable to erosion.
Approximately 20,000 years ago, during the most recent ice age, the cycle of freezing, thawing, and re-freezing of snow on the plateau caused meltwater to filter into the cracks in the rock and enlarge them. Eventually, this resulted in large portions of the rock crumbling away, leaving the deeply eroded formations that now comprise the Bosque de Rocas.
The surface area of the district is 607 sq km (234 sq mi). The climate is cold and dry, with temperatures that vary between 13.8 °C and -8 °C (59 °F and 18 °F).