These massive waves can be taller than the biggest skyscraper, travel at the speed of a jet plane and when they reach land, rear up and turn into a terrifying wall of water that destroys everything in its path. These unstoppable, uncontrollable forces of nature caused the ruin of an entire ancient civilization, may have played a small part in the demise of the dinosaurs, and in World War II were used as a weapon. Yet astonishingly, two men who surfed the tallest wave in history - half a kilometre high - survived.

Iain Stewart travels across mountain ranges and glaciers to reveal ten remarkable stories about avalanches. Over a million avalanches happen throughout the world each year, and yet we know more about the surface of the moon than we do about the chaotic turbulence inside an avalanche. Scientists have had to put themselves right inside a raging avalanche to find out more.

Iain Stewart takes a grand tour of the world's most extraordinary volcanoes. With explosions that dwarf atomic bombs, waves of hot turbulent gas that travel at the speed of sound and rivers of hot molten rock that destroy everything in their path, volcanic eruptions can literally move mountains in minutes and are rightly thought of as among the most destructive and deadly events in nature. But there is far more to volcanoes than death and destruction, because without them the planet would be a very different place - there would be no atmosphere and no life.