Cap Blanc-Nez is a cape on the Côte d'Opale, in the Pas-de-Calais département, in northern France, culminating at 134 m. The cliffs of chalk are very similar to the white cliffs of Dover on the other side of the Channel in England. Cap Blanc-Nez does not protrude into the sea like a typical cape but is a high point where a chalk ridge has been truncated by the sea, forming a cliff that is topped by the obelisk of the Dover Patrol Monument, commemorating the Dover Patrol which kept the Channel free from U-boats during World War I.