An Underground Lake in the Mine

There was a beautiful underground lake in the gypsum mine.
The Gypsum mine was open from 1848-1912. Gypsum was used for
fertilizer. They took out 3000 kilos every day. In 1912 there was a
water break disaster with 20 million liters of water letting loose.
The mine was then closed down.
It was reopened in WWII with a Concentration Camp built right above it
with the prisoners working in the mine for a year.
The mine is now used for visitors and local events.
There is a festival hall in the mine where they have events such as
musicals like 'Man of LaMancha'.