Kalø Castle was built in 1313 by King Erik Menved to protect Århus Bay. The future King of Sweden, Gustav Vasa, was held prisoner here in 1519. Today, the fortress is no longer merely a romantic ruin. As you head down towards Vrinners in the south (7km), you cross the Mols Bjerge (Mols Hills), an area of picturesque hills. The summit, Agri Bavnehøj (137m), offers splendid panoramic views. The lake of Agri doesn't flow into any river. Poskjær Stenhus, between Agri and Knebel, is a funerary chamber surrounded by a circle of 23 enormous rocks and dating from 2000 B.C.