The Trail du Ballon d'Alsace 20 km is a late-summer trail race held in Sewen, Haut-Rhin, eastern France. While the distances are modest for mountain running, featuring 10 km and 20 km options, the 20 km route includes 930 meters of ascent.
The 10 km race offers 350 meters of elevation gain, making the event suitable for novice trail runners or those seeking a challenging two-hour mountain run. Children's races in U7/U10 and U12/U14 categories are also available, contributing to a local club and family atmosphere rather than a large ultra event.