Meaning “glacier of rivers”, Vatnajökull is the largest glacier in Europe, covering almost 10 per cent of Iceland. Underneath the ice is a frozen world called the Crystal Caves, a hidden labyrinth of blue chambers and tunnels that change with the seasons.
In the summer sunshine the surface of Vatnajökull’s thick glacial ice melts, and the resulting water flows into holes and cracks on the surface. Underneath the glacier, rivers of this meltwater cut through the ancient glacier ice, leaving behind magnificent glacial caves. Each year the caves appear in different places – local guides scout their location and take tourists 
to those that are safe to visit.
Advancing Ice. Stretching for 30 km (19 miles), Perito Moreno (left) in Argentina is an unusual glacier because it is advancing, rather than shrinking. Heavy chunks of ice break off regularly, dropping into the shimmering waters of Lake Argentino.
