From the top of the Puy Mary, the view takes in the Cantal mountains, Europe's biggest volcanic range. Originally a gigantic volcano, it has been worn down by millennia of erosion. The puys have taken on various shapes: Puy Griou is shaped like a peak; Puy Mary is pyramidal, while the highest, the Plomb de Cantal, resembles a huge fist. Many glacial valleys, home to several passes, radiate outwards via a number of passes, such as the Pas de Peyrol, the highest road in the Massif Central, leading to the Falgoux cirque.