Very complete route that runs along the tracks and trails that go up the Arzabal mountain. Starting from the village of Eugi, just at the exit of the same, we will ascend comfortably along the cemetery track until we reach the beginning of the descent. A descent that has everything, roots, rock gardens, flow and technical sections. High difficulty level, suitable for expert bikers and runners. At the end of the descent we will have to cross a river that depending on the season has a lot of flow, CAUTION, from there we will flatten out on a track until we take the NA-138 road heading SOUTH to the village of Eugi.