The mine has been producing salt since the 1200s and was the source of one-third.
They began producing salt in limited amounts, as their main industry was lumber.
This region produced high qualified salt from ancient time and expensive marine product.
In 1948, he started a company that produced salt; it changed its name to Nissin 10 years later.
A second company, equally anonymous, had set up an installation that could, at the same time, produce drinking water and salt.
On the west side of the island there is a small shallow lake that produces salt in the dry season.
These were used to produce brine and salt for some hundred years.
The oil was burned to evaporate brine and produce salt.
This can be undone again to produce salt and sand separately.
Yomju produces enough salt to satisfy 10% of national demand.