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.
Conservation issues A National Park of 73,500 ha was established in the upper drainage of the Lar river in 1976, but this reserve has since been reduced in size to 28,000 ha and downgraded to Protected Area. No conservation measures are known to have been proposed and there are no known threats to the site.