Located in Kohgiluyeh and Buyer Ahmad and Esfahan Provinces, this mountainous 93660 ha area has been protected since 1990 thanks to its intact nature and biological richness. The region is mountainous and has permanent glaciers and high-flow rivers. The altitude range of 1360-4413 m, and mean annual precipitation and temperature of 650 mm and 14 °C, respectively have resulted in cold sub-humid and humid climates with prolonged frost periods at higher altitudes. The eastern half of the region is mainly covered with grasslands whereas the wetter, more bio-diverse western half harbors forest vegetation cover. 440 plant species have been identified in the region. The main plant species are oak manna tree, Turk terebinth pistache, willow, almond, honeysuckle, Montpellier maple, thorn, ash tree, mazzard cherry, juniper, pear, sour cherry, tansy, astragal, prickly thrift, prangos, thyme, giant fennel, crown imperial fritillary. sandwort, Psychrogeton obovatus, goafs beard and flax. Dena is one of the natural sites for plane tree in Iran. Some of the main animal species of the region are Persian squirrel, wild goat, wild sheep, wolf, jackal, common fox, brown bear, weasel, leopard, wild cat jungle cat, Eurasian lynx, Caspian snowcock, bearded vulture, golden eagle, bonelle's eagle, different buzzards, sparrow hawk, Lavantine viper and Persian horned viper. High biodiversity, snow-clad Dena summits, beautiful landscapes, high-flow rivers and relatively proper access roads have facilitated tourist, athletic and research activities in the region.