For more than a hundred million years, sea turtles have been swimming in the world's oceans. These magnificent, long-lived creatures spend their lives in the water, coming ashore to lay their eggs. Upon hatching, the baby turtles leave the nest and enter a dangerous world of storms and predators. The females will return to the same beach to lay their own eggs when they reach maturity a decade later. Today, there are many types of sea turtle: the grass-eating green turtle; the sea sponge-eating hawksbill; the olive ridley; the Kemp's ridley, which is the smallest species; the loggerhead; the flatback of Australia; and the giant leatherback. Having escaped the mass extinction that wiped out the dinosaurs, these ancient reptiles today face new dangers that threaten their survival: pollution, hunting, and the destruction of their nesting grounds.