With pressure silently building for over 300 years, scientists investigate the potential destruction when a megaquake hits the region of Cascadia, North America.
Why the Atlantic island of La Palma has collapsed several times in landslides, and how another could cause a tsunami powerful enough to cross the ocean and devastate the US coast.
Documentary exploring what lies beneath the Earth's crust, beginning with the world's largest volcano, located underneath Yellowstone National Park.
