Pluragrotta

Pluragrotta is a cave in Rana Municipality in Nordland county, Norway. It is the deepest cave in Northern Europe. Most caves in Rana, of which there are some 200, are not suitable for diving. A popular cave diving destination, Pluragrotta attracts more divers than any other cave in Scandinavia. Visibility in the cave waters is high. The cave's passages were formed by the flow of the Plura river over limestone, and the cave system includes marble formations. A number of species have been identified in the cave ecosystem. Diving became possible in Pluragrotta with the damming of lake Kallvatnet in the 1960s. There have been multiple injuries and fatalities among cave divers at the site, which is accessible year-round.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).