Wikipedia
Grønligrotta
Grønligrotta (or Grønligrotten) is a karst cave in the municipality of Rana in Nordland, Norway. It is located in the valley of Røvassdalen, and was first explored in 1914. It has a total depth of 107 meters and explored length of two kilometers. It is probably connected to the nearby Setergrotta. The cave is equipped with artificial lights and open for tourists.