Areas of extensive and exceptional rock exposure, where even the glaciers fail to invade the rocky landscape, are known as Antarctic 'oases'. However, unlike the fertile oases of hot deserts these represent some of the harshest environments on our planet.From such areas, largely confined to the margins of the continent, nearby islands, and the Antarctic Peninsula, geologists are able to collect the rock samples and fossils of ancient life which provide them with windows on the history of Antarctica through hundreds and thousands of millions of years.