Marmorslottet, the castle of marble, is a stretch of river where the water has carved white and grey marble into smooth shapes. It lies in the Glomåga river in Rana, about 45 minutes by car from Mo i Rana. The walk in is 1.2 km one way but graded difficult. Go in summer, when the water is lower, and keep away from the current.
This guide is for visitors from abroad. Norwegians can read our Norwegian version.
What Marmorslottet is
River and rock
Store norske leksikon describes Marmorslottet as a limestone and marble landscape in the river Glomåga. It lies at the far north-west end of Fisktjønna nature reserve. The area is rich in caves and potholes, which Norwegians call jettegryter.
Why it looks the way it does
The river has worn the rock into channels and bowls. It is a place for slow walking and looking, not for swimming.
How to get thereBy car from Mo i Rana
Allow about 45 minutes from Mo i Rana. Norwegian Wikipedia gives the route: the E6 east to Røssvoll, then road 7366 Røvassdalsveien. Go straight on at Sveinåga bridge, take road 7370 Langvassveien west, and then Svartisdalsveien, road 7368.
The last stretch is a narrow gravel road past farmyards. Drive slowly. Parking at the end costs NOK 70 per day, paid by card or Vipps.
By train
The Nordland Line timetable valid to 12 December 2026 has a train from Trondheim S at 07:30 that reaches Mo i Rana at 14:28. There is no night train at present, because of a shortage of locomotives after an accident in autumn 2024. SJ expects it back during January 2027.
By plane
Today only Widerøe flies to Mo i Rana. Widerøe flew 93 direct departures from Trondheim to Mo i Rana in October 2026. There were no direct flights from Oslo that month. A new airport at Fagerlia opens on 30 September 2027, and Røssvoll airport closes on 2 September 2027.
The hike
Length and time
The route is 1.2 km one way with about 50 m of climbing. Visit Helgeland gives 20 to 40 minutes each way. It is not suitable for wheelchairs or prams.
Finding the way
There are no signposts after the car park. Where the trail forks, turn left. Look at the route map on Visit Helgeland before you go.
The descent
The stairs and rope in the steepest part of the descent disappeared in 2021, probably taken by ice. The rock is very demanding when wet. Wear shoes with a good grip for the path.
Shoes off on the marble
Visit Helgeland asks you to take your shoes off when you walk on the marble itself. Bring a towel and dry socks.
Rules and safety
The river
The area is not secured, and the current in the river is strong. Do not walk close to the edge of the channels. Keep children close at all times.
No drones, no fires
Drones are banned. Fires are not allowed. There are no toilets or bins, so take everything home with you.
When to go
Check conditions on Visit Helgeland’s page before you go, and avoid the hike after heavy rain or snowmelt.
Pair it with Grønligrotta
The cave
Grønligrotta lies 20 km north of Mo i Rana and is the most visited marble cave in the Nordic countries. It has lights, stairs and walkways. The guided tour goes 400 m into the mountain and takes 45 to 60 minutes.
Tickets and hours
Adults pay NOK 260, with free parking, and children aged 4 to 14 pay NOK 180. Children under 4 go free. You buy tickets at the Grønlia farm reception by cash or card, and no booking is needed.
The page we opened lists tours from 25 to 30 June at 10:00, 12:00 and 14:00. In July, tours run every hour from 10:00 to 17:00. From 1 to 9 August they run at 10:00, 12:00, 14:00 and 16:00, and the cave closes from 10 August.
Dress for the cold
It is 4 to 8°C inside, so bring a jacket. Dogs are not allowed. More than 4,000 m of the cave has been mapped.
Our verdict
Marmorslottet is a short walk with a big reward, but only in dry summer weather. Pair it with Grønligrotta on the same day in July. If it has rained hard, do the cave and skip the river.
More nature trips are in our fjords section. Read our Norway travel guide to plan the rest of the trip.
Parking at Marmorslottet costs NOK 70 per day, and the cave costs NOK 260 for an adult.