Kalvø is a tiny island of only 17 hectares, at the base of Genner Bay. It is part of a tunnel valley. There is a dam between Kalvø and the mainland, which you can ride along to get to the island. A shipyard was built on the island in the 1800s, and in the 1960s gravel mining began. The area is now a wildlife reserve, and in the spring and autumn months, there are many opportunities for bird watching. Take a 3km ramble around the island exploreing the stones brought to this area, from Norway and Sweden, during the Ice Age.