Scientists explore the extraordinary mass nesting behaviour of the olive ridley sea turtle, and reveal the hidden world inside a turtle nest. Locals call it the arribada, Spanish for “arrival”: the magical days and nights when tens of thousands of sea turtles come ashore on Costa Rica’s Pacific coast to lay millions of eggs. In Turtle Beach, a documentary from The Nature of Things, Canadian naturalist and cinematographer Hugo Kitching follows a team of international scientists on a groundbreaking expedition to uncover the mysteries of this rare phenomenon.