Grønligrotta

Grønligrotta is a marble karst cave in Rana Municipality, Nordland county, Norway, opened to visitors with artificial lighting and a guided route. It lies in the Røvassdalen valley, a short drive north of the town of Mo i Rana, and is one of the most accessible underground attractions in northern Norway.

What is Grønligrotta?

The cave formed in marble and limestone, carved over millennia by water running off the surrounding mountains. It was first explored in 1914. It reaches a depth of 107 metres and has an explored length of about 2 kilometres. Cavers consider it probable that the system connects to the nearby Setergrotta, which suggests the known passages may be only part of a much larger network.

Only a section is prepared for visitors. The passages are fitted with artificial lights, so no caving gear or experience is needed.

What will you see on the tour?

The route passes glacial potholes worn by meltwater, stalactites, an underground stream and a small waterfall hidden below ground. It is a good chance to see up close how water has shaped rock over thousands of years. Visits are guided only, and the guide explains the story of the cave's exploration and how its formations developed.

How long does a visit take?

Sources give anywhere from about 30 to 60 minutes. Tours leave at set times during the summer season with no advance booking: buy a ticket and join the next group.

When should you go and what should you bring?

The cave is open mainly in summer, roughly June to August. Hours and prices change from year to year, so check current details with the operator before travelling. Inside it is cold, usually 4–8°C (39–47°F), so bring a sweater even on a hot day, plus sturdy closed shoes. The ground can be wet.

Frequently asked questions

Can I enter the cave on my own? No. Visits are only possible in a guided group.

Do I need to book? In season usually not. Tickets are sold on site and you join the first available tour.

Is it suitable for children? Yes, the route is lit and set up for tourists, but children should dress warmly.

Are there facilities nearby? There is a café close by and camping is available in the area, which makes it easy to combine the cave with a full day out around Rana.

How do I get there? Most visitors drive from Mo i Rana, heading north toward the Røvassdalen valley. The trip takes roughly half an hour.

Why visit?

Grønligrotta combines easy access with a genuinely northern, mountain atmosphere. It is a short, rewarding stop for anyone travelling through Helgeland, especially on a rainy day when clouds hide the views outside. Afterwards, stay in the area and explore more of Rana municipality, which sits close to the Arctic Circle.