Among them, the Mundok Migratory Bird Reserve (MMBR) has provided habitat for birds as it has a diverse wetland ecosystem like a large area of tidal flat, the part where a river joins the sea, reed fields, swamps and bushes distributed on islets and along the coast, and the reclaimed rice field, mudflat, seawater, etc.

The MMBR, designated in Juche 84 (1995), is located in Mundok County of South Phyongan Province, the DPRK, and covers an area of over 3700 hectares.

280-odd species of birds, including black-faced spoonbill, Eurasian spoonbill, hooded crane, Chinese egret, inhabit the MMBR. And more than 80000 water birds of over 120 species like great knot, Terek sandpiper, lesser sand plover and red-necked stint flock there in spring and autumn.

22 major dominant species of water birds have been observed there and they number over 76000. 22 species of water birds are globally threatened, among which there are 2 critical, 7 endangered and 13 vulnerable species.

Over 50000 swan geese known as a vulnerable species worldwide were observed in October 2018 alone.

Animals like 20-odd species of amphibians and reptiles, 60-odd species of fishes, 21 species of crustacean, tens of species of epifauna, 7 species of annelid and 16 species of mollusk, and hundreds of species of plants have been founded there to supply water birds with sufficient foods and breeding and habitat conditions.

Numbers of field and mountain birds including yellow-breasted bunting, western crowned warbler and little owl and over 20 species of animals like roe deer live in the MMBR.

Every year, shorebirds wearing flags and bands flied from other countries including Australia and New Zealand are observed there.

The wetland in the MMBR became a wetland of international importance (Ramsar Site), the first of its kind in the country, in January 2018 and was registered as the Network Site of the EAAF (East Asian-Australasian Flyway), one of the eight international flyways for migratory waterbirds, in April that year.