National Geographic recently followed a team into one of the earth’s deepest high-altitude cave networks, known as Dark Star, providing an alluring glimpse into the remote underworld.

The expedition takes place in Uzbekistan and plunges nearly 3,000 feet beneath the earth’s surface through a yawning maze of caverns currently spanning eleven miles. Although not the deepest cave, much of Dark Star is yet to be explored. The system was first discovered in 1984, with seven entrances surveyed thus far, but the remoteness of its location makes for difficult exploration.

National Geographic writer Mark Synnott joined a 31-member team of experienced cave climbers and enthusiast scientists on an unforgettable journey into the Boysuntov mountain range. The expedition launched out of the capital of Uzbekistan hundreds of miles by bus and off-road vehicle, following the ancient Silk Road to Samarkand, and then on to Boysun.

Dark Star is situated near the Afghan border and required a grueling hike, accompanied by fifteen donkeys, and two days on foot to reach base camp. The real journey began nearly 12,000 feet above sea level at Xo‘ja Gurgur Ota, a limestone cliff that houses the entrances into Dark Star.

Part of what makes investigation of this underground world so difficult is the necessity for advanced rock climbing and rappelling skills — just to reach the entrance to the cave. Synnott and the team began their descent into the dark depths via the main passageway, Izhevskaya.

The expedition led the team through Dark Star’s winding frost-tinged caverns, often connected by tunnels only a a few feet wide and other times pouring into massive chambers nearly a hundred feet tall. The Full Moon Hall is the most impressive documented example of this, extending 820 feet in length. 

Synnott was guided through Dark Star to Gothic Camp, an open area situated midway through the tunnel system wide enough to house multiple tents. From there the writer documented vivid accounts of treks throughout one of the deepest places in the earth, including the discovery of a tunnel beyond a 150-foot waterfall that was up until that point, the end of the Dark Star expedition road.

Rare photographic images and footage transport viewers through the screen into the beautiful depths of Dark Star. A full trip account can be viewed on the National Geographic website.