The Trangen cabin was a hiding place for King Haakon VII and Crown Prince Olav in May 1940. On the property, closer to the water, stands a sauna that was built as a washhouse for the king. It is a simple cabin of timber framing approximately 2x4 meters with a sauna stove and chimney. The cabin consists of changing room, hallway, and sauna room. The roof is covered with roofing felt.
The sauna was set up hastily so that the king could have the opportunity to wash in privacy. It is colloquially known as "The King's Sauna."