A double summit, double peak, twin summit, or twin peak is a mountain or hill that has two summits, separated by a col or saddle.
One well-known double summit is Austria's highest mountain, the Großglockner, where the main summit of the Großglockner is separated from that of the Kleinglockner by the Glocknerscharte col in the area of a geological fault.[1] Other double summits have resulted from geological folding. For example, on Mont Withrow in British Columbia, resistant sandstones form the limbs of the double summit, whilst the softer rock in the core of the fold was eroded.[2]
Triple peaks occur more rarely; one example is the Rosengartenspitze in the Dolomites. The Illimani in Bolivia is an example of a rare quadruple summit.
Well known double summits are (roughly from east to west):
Pilot peak and index peak in Wyoming