St Helena and Ascension are two of the most isolated islands in the world, the tips of enormous volcanoes rising from the depths of the Atlantic Ocean between southern Africa and Brazil, 800 miles apart. St Helena was formed some 14 million years ago, but Ascension is only a tenth as old. The difference in age confers a special interest. On St Helena, the few succesful colonizing plants and animals evolved and diversified in isolation for millions of years; mature natural communities developed and the landscape was transformed. In contrast, the ecological youth of Ascention leaves it strange and forbidding, but with its own biological surprises and its own austere beauty. Since the arrival of humans 500 years ago, the fauna and flora of these islands have changed irrevocably. The vast seabird colonies have been decimated and many plants and animals have become extinct or are teetering on the brink. There is still an opportunity, however, to appreciate what remains and to understand what has been lost. For any naturalist, questions abound. How did the islands originate? How did their unique species arise? What lessons can we learn from the saga of destruction and how can we care for the remaining wildlife in the face of human activities? The authors address these and many other fascinating questions. They have tried to provide reliable scientific information in an easily accessible form, and at the same time to convey something of their own enthusiasm for the natural history of these remarkable islands.