A real sporting challenge, this route is aimed at experienced cyclists. Why not do it over two days? Take a break to explore the cultural and heritage attractions of Delle, Porrentruy, Boncourt and Brebotte. Combining greenways (Eurovélo6, francovélosuisse, voie verte de la Largue in Alsace) and steep country roads, this loop is the most difficult. We like: the Maison de la Nature in Altenach, the stork park in Seppois and the Bison Park in Boncourt*.