The Woff Cave is a cave near Tofoten where Woff like to make their nests.
The cave is located inside a hill at the foot of Mount Fødsel. It has an opening in the top. On the inside the cave has many tunnels and holes in which Woff make their nests and hatch their eggs.
The cave is mentioned in "Hilda and the Fairy Village" when Astrid learns that The Pooka stole a woff egg, and orders Loam to bring it back. However, none of the characters are seen visiting the cave in this story.
The cave is featured more prominently in season 3 of the animated series, in the episode "Chapter 1: The Train to Tofoten". In this episode, rather than sending Loam to return the Woff Egg to the cave, Hilda, Johanna, David, Frida, Tontu, Twig and Alfur bring the egg to the cave themselves. They watch the egg hatch. When the Woff wake up and accidentally destroy part of the platform they were standing on, Johanna instructs everyone to jump on a Woff and let the Woff carry them out of the cave.
