This sanctuary, covering an area of 32 square kilometers, consists of Man, Tongbon and Sobon lagoons in the area of Rason and Al Islet on the East Sea of Korea, eight kilometers away from the area.

The area has good conditions for ecological environment and Man and Sobon lagoons, in particular, are fit for the standards the world set as marshland for migratory birds.

The Rason reserve, one of 30-odd sanctuaries for migratory birds in the country, has been listed as an IUCN reserve. And its registration as a reserve of RAMSAR, an international body, is now under discussion.

The reserve serves as a main habitat of migratory birds flying in the Asia-Pacific region.

At least 200 species of sea birds have been observed in the area up to now.

The recent field survey, made by ornithologists of different countries, shows that a large number of bird species on the way to extinction inhabit the area, with more than 40 000 migratory birds observed in around Man and Sobon lagoons close to the sea.

Among them are Anas Formosa, Coturnix japonica, Numenius madagascariensis, Grus vipio, Grus monacha, Cygnus olor, Ans falcate, Larus relictus, Emberiza yessoensis, Calidris tenuirostris, Clangula hyemalis, which have been listed as birds to be protected worldwide.

The reserve is of weight significance in preserving the ecological diversity.