The world’s greatest underwater gypsum cave

ORDA Cave is located underneath the western Ural Mountains in the Perm region in Russia, and is known as the most beautiful cave in the world among divers. The length of this underwater gypsum cave is over 5.1 kilometers with around 4.8 kilometers being under water. This makes it one of the longest underwater caves and the largest underwater gypsum cave in the world.

Exploration of Orda Cave began back in 1992, but it is so huge in space that to this day the cave has not yet been fully mapped. It is full of big grottos, some of which are the size of a soccer field.

It is a gypsum cave with chalky white gypsum interior formed about 300 million years ago. Gypsum is highly soluble in water, which result in structural change over time. As new passages form, others become blocked; geologically the cave has never stopped rearranging itself through the millennia. Inside, the cave resembles a maze. The vast gypsum deposits here help to filter the water to keep it amazingly crystal clear.

In January, NHK, Japan’s broadcasting organization conducted a first-ever filming of its inside using 4K highdefinition cameras under the extreme environment; outside temperature is -20°C and the water in the cave is -6°C. A huge space at the middle of the cave, which nobody was able to film since it is pitch dark, is being called “water cosmos” by divers. When it was lighted, it was a dream like world, 40 meters wide, about 100 meters to the end, and over 10 meter-high gypsum walls with translucent crystalline shapes and a pure white color. Absolutely clear water gives one the illusion that they are not swimming but rather flying in space. Such a mysterious and breathtakingly beautiful sight has never been seen by human eyes.