Sniff’s cave has smooth walls and the floor is covered with soft sand. A gap in the roof lets in some warm sunlight. Sniff finds his cave in the novel Comet in Moominland, and while waiting for the world to end some inhabitants of Moominvalley hide in the cave.
In Finn Family Moomintroll and Snufkin hides the Hobgoblin’s hat in the cave. Shortly after this, to their dismay, The Muskrat unexpectedly moves into the cave, searching for a more quiet place to live in.