Kwangpho is the third largest natural lake of Korea. It was a bay of the sea. It is a lagoon formed by the seaside upheaval and sedimentation.
It is lying between Hamju and Jongphyong Counties of South Hamgyong Province.
The lake covers an area of 9.02 square kilometres and its circumference is 31 kilometres.
More than 60 rivulets flow into the lake. The lake is gradually becoming shallower because of the sedimentation of the rivulets. Especially a delta has been formed at the mouth of the Wonsu Stream, the largest of the rivulets flowing into the lake, dividing the lake into upper and lower parts.
The lake bed consists of mud and sandy soil. The upper part is mainly covered with mud and the lower part with sandy soil mixed with 80 percent of sand.
The lower part is directly linked with the sea and the water contains a high rate of salt.
Low hills and mounds are found on the southeast shore of the lake and flatlands in the north and the west.
The lake is dotted with a number of islets and surrounded by big and small ponds, morasses and paddy fields.
The lake has feed grass, floating plants and zooplankton and a lot of carps, goldfish, corbiculae and mud-snails.
The lake is used for breeding duck and fish. A rest home for working people has been built on the beautiful shore.
Kwangpho has been registered as a natural monument.