Mûr de Bretagne climb is a focal point for cyclists in France’s most cycling-obsessed region, Brittany. It is short but tough, actually the first half of the climb is much tougher, where the gradient usually stays above 10%. The second half is much easier. The climb is 2.21 km long. Over this distance, you gain 144 meters of elevation. Thus, the average percentage is 6.5%.