Until about 8,000 years ago Britain was part of the European continent. Then the ice melted, rivers flooded, seas rose and, hey presto, the land that joined us to France, Holland and Denmark disappeared under water. The excitable Tony Robinson and his team of eager archaeologists set about investigating the vast, flat landscape that's now under the North Sea and the English Channel. But it's one of the most difficult archaeological sites to work on. While the local fishermen regularly bring up ancient bones from the seabed, Robinson and co merely bring up their dinner. It's worth the discomfort though: vast mammoth bones, the jaw of a sabre-toothed cat, a lion's canine and sophisticated tools are among the treasures that enthusiasts have uncovered.