This mountain bike route starts in Islantilla and follows several sections of the Piedras River, reaching its reservoir. Among other points of interest near this route is the La Tavirona Bridge, an iron bridge that once carried the Huelva-Ayamonte railway line. Built in 1931 using the remains of an old train carriage, it is an impressive 80-meter-long engineering feat. The route presents a moderate challenge due to its ascents and descents.