A well-built roadway from the early Viking Age at the Rösaring archaeological site in central Sweden is assumed by archaeologists to have been used for processions. The road is here examined in relation to its environment, the sun and the moon, the Milky Way and the rainbow. The aim was to extend landscape archaeology to include natural phenomena and their impact on prehistoric monuments as an aid to conventional archaeology. The play of sunlight over the road at noon was found to be particularly spectacular at midwinter and well-suited for enhancing the performance of rites which could have taken place at a large mound at the south end of the road, possibly in connection with the cult of the Norse fertility god Freyr.