Große Weserrunde is a long-distance cycling marathon held in August, starting and finishing in Rinteln. Participants can select from six routes, ranging from 80 km to 350 km. This offers options for both dedicated endurance cyclists and those seeking a shorter ride along the Weser River.
The longer routes extend towards Hann. Münden and Porta Westfalica before looping back to Rinteln. An estimated 1,500 participants are anticipated, potentially setting a new record for the event. The marathon originated as a casual ride and has since developed into a recognized cycling event, maintaining its core emphasis on long-distance cycling by the river.