The ramparts were surrounded by a ditch within which was an unclimbable fence. The guides were not able to pass an unclimbable overhang that separated them from Kurz. The enemy position was behind the Wadi Zigzaou, wide, with almost unclimbable sides high. Frances is pushed into a sinister mansion enclosed by unclimbable walls. It was first climbed in 1959 despite a local tradition that it was unclimbable.