Many of the Galapagos' volcanoes that brought about its existence remain active, and there's amazing footage of an eruption of the Sierra Negra. Marine iguanas leap off lava cliffs into billowing surf; giant tortoises are groomed by Darwin's finches; and the waved alabatross shows off with a magical courship display.

Natural history series exploring the Galapagos Islands, which lie 1,000 kilometres off the coast of South America. From flightless cormorants hunting underwater to giant tortoises courting on the rim of an active volcano, a look at the hidden side of Galapagos, revealing why it is such a fascinating showcase for evolution.

Natural-history series exploring the Galapagos Islands, where the forces of nature can be brutal. It's a land of fire, astride the equator, and at the mercy of the elements. This concluding episode reveals how, through time and isolation, animals and plants have evolved the most surprising ways to cope with the profound geological and climatic forces. In the new millennium, with a growing interest in this delicate microcosm of our planet, come ever-increasing challenges.