In Switzerland, the Austroalpine nappes have been eroded away except for a few isolated outcrops called the Sesia unit and the Dent Blanche klippe (the Matterhorn is the most outstanding example of an Austroalpine klippe). These remaining Swiss nappes have a different tectonic and metamorphic history than their counterparts in Austria, which is why they are not always considered a part of the Austroalpine nappes.