The Vegfjellan cave system is located beyond the Arctic Circle, in the Nordland district of Norway. The entrance to the cave is situated in the massif of the same name, on a steep fjord slope at an altitude of 60 meters above sea level. This cave has been explored since 2016, and in March 2023, another expedition, the tenth Veggfjellan Winter Expedition X, took place.

Typical for caves located in the far north, there is a large water flow in summer, which makes diving impossible. Therefore, despite the extremely difficult conditions, penetrating cold, and complicated logistics, diving takes place during the polar winters.

The main goal of the 2023 Veggfjellan winter expedition was to explore an extensive underwater passage reaching a depth of about 50 meters, discovered during the previous winter expedition.

The first stage of the expedition was equipment transportation. This time, all the necessary equipment was transported by helicopter. The total weight of the equipment needed for the cave action amounted to 600 kilograms. Unfortunately, in the final stage, it was still necessary to laboriously tow heavy bags to the inside of the cave, which took almost two full days.

The first dives were carried out on the third day of the expedition. Due to the great depth of the dives and the low water temperature, only 1 degree Celsius, the team used CCR rebreathers (KISS Sidewinder, JJ, and Flex). The team members managed to dive in the deep passage, in the Waterfall Cave. Reaching it takes quite some time, as it requires passing through a series of shorter siphons. During the expedition, over 200 meters of corridor were discovered at depths reaching 50 meters.

In the following days, the team continued the exploration and also collected samples of small creatures found in the siphons. These samples were handed over to scientists for further research, including species identification and to shed new light on the ecology of this underground environment.

Thanks to the team's efforts and deep diving in extremely challenging conditions, the newly discovered sections of the Vegfjellan cave system were mapped, which will help better understand the extent of its corridors and connections with other cave entrances.