The site comprises 20 km of the upper Lar valley in the high Alborz Mountains, from 2,450 m to peaks at 4,540 m. It lies above the Lar Dam, c.10-30 km upstream from the small town of Polur and c.40 km north-east of Tehran. The Lar is in the Caspian watershed, but at this point lies in a rain shadow and the area is relatively arid. For much of its length, the river meanders across a broad, flat-bottomed valley c.500-1,000 m wide. Habitats include a fast-flowing river with extensive shingle banks, patches of dense riverine Salix and Tamarix scrub (with a few trees up to 7-8 m high), small areas of natural wet meadow, open hillsides with steppic vegetation, a number of small, spring-fed alpine meadows in side valleys, and the high crags and summits of neighbouring peaks. There is grazing by sheep, goats and horses. The area was a regular bird-ringing site of the Department of the Environment's Ornithology Unit in the 1970s.
See box for key species. The area supports a typical high Alborz avifauna, including a good population of Tetraogallus caspius, and also appears to be of considerable importance as a staging area for migrant passerines (e.g. Phylloscopus trochiloides nitidus), especially in autumn, when the dense shrubbery and wet meadows along the river provide rich feeding habitat. At least 97 species have been recorded in the valley.
Non-bird biodiversity: None known to BirdLife International.
BirdLife International (2020) Important Bird Areas factsheet: Lar River Protected Area. Downloaded from http://www.birdlife.org on 19/09/2020.