The Svellen Peninsula is a subcontinent in the northeast of Karelia. Most of the peninsula consists of rugged hills growing into the Surtheim Mountains, which include the especially tall section known as the Keel. The lower lands are generally forests of pine, birch, and alder. To the north, it becomes heavily glaciated.
The realm of Svellheim occupies the entirety of the peninsula, except for a small portion to the south that is part of Periaslavl.