Ben Nevis is all that remains of a Devonian volcano that met a cataclysmic end in the Carboniferous period around 350 million years ago . Evidence near the summit shows light-coloured granite ( which had cooled in subterranean chambers several kilometres beneath the surface ) lies among dark basaltic lavas ( that form only on the surface ) . The two lying side-by-side is evidence the huge volcano collapsed in on itself creating an explosion comparable to Thera ( 2nd millennium BC ) or Krakatoa ( 1883 ) . The mountain is now all that remains of the imploded inner dome of the volcano . Its form has been extensively shaped by glaciation
Thera
Minoan eruption
Ben Nevis