World's Longest Underwater Gypsum Cave

A team of daring cave divers working on Orda Cave Awareness Project have produced an incredible series of photos of the longest underwater gypsum crystal cave in the world. Located near Orda village in Perm region, Ural, Orda Cave is also the biggest underwater gypsum crystal cave in the world and second in Eurasia in terms of volumes of its galleries that stretch up to five kilometers.

Over a period of six months, famous underwater photographer, journalist and dive-instructor Victor Lyagushkin led the team of cave divers and took stunning images of the cave at less than zero degree temperature.
The location of the cave in Ural region, which is known for rich mineral deposits in Russia, may be linked to the gypsum content in Orda Cave, which has transparent water because of the mineral. The water is so clear divers can see over 50 yards ahead of them.
Here are some pictures from the expedition.