Orda Cave is a gypsum crystal cave located under the western Ural Mountains, with its mouth opening near the shore of the Kungur River outside Orda, Perm Krai, Russia. The system of caves is more than 3.2 miles long, most of which is underwater, making it the largest underwater gypsum cave in the world. As for visibility, it extends about 50 yards.

All of this makes for ideal diving conditions.

It’s so appealing that in 2011, journalist, underwater photographer, and dive instructor Victor Lyagushkin led more than 150 expeditions in the cave. The photographs taken by him and his team were then published on the Orda Cave Awareness Project website, which Lyagushkin created along with Bogdana Vashchenko, a diving journalist. The project focused on bringing awareness to the cave through photography, as well as how to protect it.

Fueled by their passion for protecting the cave, the divers even used a funnel system that directed the air bubbles they produced toward the mouth of the cave, veering it away from the delicate gypsum walls. The diving team was also the first to capture a spherical panorama of an underwater cave.

The cave gained mass attention again last year when freediving champion Natalia Avseenko recreated the “Lady of the Orda Cave” myth in a photography series shot by Lyagushkin.

According to a post on Behance, “There is a legend that there is a Lady of the Cave who is very beautiful and charming. The lady is taking care of all the divers entering that incredible ‘natural cathedral.'”

Avseenko and Lyagushkin traveled to depths of 56 feet, with temperatures as low as -9 °F, over the two days it took to complete the series.

Check out the video below that features a scuba diver’s tour of the cave, and look through the Orda Cave Awareness Project gallery.

Image is a screenshot from video by Kiril Ivanov on YouTube