In the Plura Valley, 30 kilometres south of Mo i Rana, a river disappears into the mountain and fills Northern Europe's largest underwater cave system. Pluragrotta stretches deep into the marble bedrock, and the only way in is to dive. The water is four degrees year-round, but winter visibility can reach 100 metres, turning the flooded passages into something closer to flying through crystal than swimming through a cave.
About 450 metres inside the mountain, past the submerged sections, the cave opens into an air-filled chamber called The Chapel. On 29 March 2024, this became the venue for the world's first concert accessible only by cave diving. As part of Bodø2024, the European Capital of Culture programme, saxophonist Håkon Erlandsen performed for an audience of around 50 certified cave divers who had swum through the mountain to reach their seats. Erlandsen already held records for the highest concert, on the summit of Everest at 8,848 metres, and the coldest, in Antarctica at minus 57 degrees. A kilometre of fibre-optic cable was laid through the cave to livestream the performance to the surface.
Plura Valley is operated as a dive centre and is open to certified cave divers. For non-divers, the valley itself is worth the detour: the river emerges from the mountain on one side, flows through a narrow gorge, and plunges back underground on the other. You can see the cave entrance from the surface, a dark mouth in white marble where the water vanishes. The centre also offers snorkelling and introductory experiences in the river section outside the cave.
About 450 metres inside the mountain, past the submerged sections, the cave opens into an air-filled chamber called The Chapel. On 29 March 2024, this became the venue for the world's first concert accessible only by cave diving. As part of Bodø2024, the European Capital of Culture programme, saxophonist Håkon Erlandsen performed for an audience of around 50 certified cave divers who had swum through the mountain to reach their seats. Erlandsen already held records for the highest concert, on the summit of Everest at 8,848 metres, and the coldest, in Antarctica at minus 57 degrees. A kilometre of fibre-optic cable was laid through the cave to livestream the performance to the surface.
Plura Valley is operated as a dive centre and is open to certified cave divers. For non-divers, the valley itself is worth the detour: the river emerges from the mountain on one side, flows through a narrow gorge, and plunges back underground on the other. You can see the cave entrance from the surface, a dark mouth in white marble where the water vanishes. The centre also offers snorkelling and introductory experiences in the river section outside the cave.