Rummu quarry
This is the original place I wanted to come to. The limestone quarry is stripped off the limestone and this is what remains. During the mining, big Soviet pumps were used to drain out the water. The story goes that when the Soviets retreated the valuable copper in the coils were stolen. The pumps stopped and the underground water soon filled up the hollows. Since this is water coming from the ground, it is very clear and cool.