Salterns located at Sinan-gun and Yeonggwang-gun in Jeollanam-do, is where sea salt is produced with the use of mudflats.
Jeollanam-do is the central region for Korean salt production. Sinan-gun holds a dominant position in the consumer market, and Yeonggwang-gun's products are essential for related industries. Yeonggwang salt is used for making jeotgal, or pickled seafood, and gulbi, or dried yellow croakers, both of which are traditionally salted foods in Korea.
There are a variety of methods for producing salt. But the process used in both regions differs significantly from others in their production process. The salt from Sinan-gun and Yeonggwang-gun is sea salt made on reclaimed tidal flats. The process begins by storing sea water in reservoirs to increase the water's salinity. When the brine reaches a specific concentration, the water is moved to checkered fields (salterns) for natural evaporation. The salterns consist of evaporation ponds and crystallization ponds, as well as brine warehouses called haeju. The salt crystals produced here are stored in silos for two to three years to remove the remaining bittern and improve the taste.
Sinan-gun is comprised of many islands, so salt production has developed over a long time. The salt from Sinan-gun usually reaches the market after the bittern is removed, which takes about a year, while Yeonggwang-gun's products are mostly used in the jeotgal and gulbi industry, after a two- to three-year-long process of bittern removal.
The salterns in Sinan-gun and Yeonggwang-gun date back to the late Joseon Dynasty in the 19th century when the process of making sea salt was first introduced from Japan. In fact, the area originally served as key sites for the then prevalent "parched salt" making methods-creating salt by boiling sea water that was previously stored in mudflats. The existence of this tradition proves that the region has long been an ideal location for salt production due to the advantages of the natural environment. Furthermore, the salterns are mainly distributed along the western coast of the Korean peninsula, which holds one of the world's five most important tidal flats. Korean tidal flats contain a high proportion of organic material, and the diverse species in these estuaries help to increase the mineral content, such as calcium, potassium, and magnesium, in the salt. As a result, sea salt accounts for the vast majority of salt supply in Korea, where fermented foods are well developed. In addition, as salt is traditionally symbolic of purification in Korean shamanism, it constitutes an important element of Korean folk culture. Finally, this salt has been used for military purposes, architecture, and clothing.
Korean salterns consist of three parts: reservoirs, evaporation ponds, and crystallization ponds. In addition, there are haeju, or brine tanks, salt silos, and resident facilities for salt makers. Reservoirs are used for storing sea water, and evaporation ponds increase the water's salinity with the help of the sun and the wind. On the fields for crystallization, the saline water turns into salt crystals. But it takes one to three years for the salt to be sold as a finished product, because the bittern is extracted during the storage process. Meanwhile, haeju, or brine tanks, are found only in Korea, where they are built in preparation for the monsoon season.
Salterns mark the borders between tidal flats and human habitats; they straddle the line between nature and culture. They are significant for fish production (as a fish habitat), purification of pollutants, aesthetic appreciation, and flood control. In addition, they serve as a rest spot for endangered migrant birds, such as plovers and black-faced spoonbills. In other words, the continuance of salterns ensures the continuance of the region's ecological system, economy, and local culture.
Salt is also produced from tidal flats in other countries, but these regions in Korea are highly valued in terms of their natural conditions, including tidal flats, the sun, and the wind, which are coupled with human creativity. In addition, although there have been changes in the usage of tidal flats and developments in power supply for transporting water, along with other technological developments, the environment and natural salt production methods maintain the outstanding value of these saltworks as a living industrial heritage.