April 30, Walpurgis Eve, is one of the greatest festivals of the year in Uppsala, with floats running the rapids, herring lunches, parties, and much more.
10 am-12 am: The River Rafting. In the mid-1970s Uppsala engineering students started the tradition of running the rapids of the Fyris River on floats. Many, many imaginatively themed and manned vessels try their luck at navigating the two falls and floating downstream through the city. It is a grand and extremely popular tradition.