where rock salt is mined
As the water from this sea evaporated, salt crystals formed from the brine, along with other useful minerals such as gypsum (used for wall plaster) and potash (used for fertiliser). Rock salt is mined at Winsford in Cheshire, Boulby in North Yorkshire and Carrickfergus in Northern Ireland.
In Europe Romania, Bulgaria, Germany, Austria Bosnia and Poland all have large deposits and mine rock salt for use all across Europe. North America also has some of the largest rock salt mines, in places such as Ontario, Louisiana and Detroit. Many old salt mines, and some of the new functioning ones, are more than just mines though, and attract thousands of visitors each and every year.