Grønligrotta

The most accessible and most visited of the caves around Mo is 22km north of town. There's electric lighting (it's the only illuminated tourist cave in Scandinavia). The 30-minute tour takes you along an underground river, through a rock maze, then past a granite block torn off by a glacier and deposited in the cave by the brute force of moving water. If you're visiting outside high season, ring the tourist office in Mo to check timing.