The Pilgrim's Route, (Pilegrimsleden) also known as St. Olav's Way or the Old Kings' Road, was a pilgrimage route to the Nidaros Cathedral in Trondheim, Norway, the site of the medieval tomb of St. Olav. The main route is approximately 640 kilometres (400 mi) long. It starts in the ancient part of Oslo and heads north along the lake Mjøsa, up the Gudbrandsdal valley, over the Dovrefjell mountains, and down the Oppdal and Gauldalen valleys to end at the Nidaros Cathedral.