The Galapagos Islands off the coast of Ecuador are volcanic in origin. Some of the lava flows are only a few years old. On a tour of the islands, you are taken on a walk over a lava field, where there are some colonising plants and insects, so the process from sharp bare lava to soil, plants and animals is visible. Also on this island there are tunnels between pools and the sea, and we saw a shark and turtles in the pool. Other depressions have flamingos.