The eastern side of the Salève dives under the molasse of the Bornes Massif while the abrupt mountain slope facing Geneva is subject to erosion. The vegetation - or its absence - enhances the limestone's layers. This side of the mountain is slit by several narrow and deep gorges, among which the Grande Varappe, which at the end of the 19th century gave its name to the activity of rock climbing in French. This discipline developed intensely there, at a time when it was only beginning.