Whales are some of the largest animals to have ever lived on our planet, but what do you really know about them? This glorious guide will take you deep beneath the ocean to explore the unseen world of whales. Learn how to recognize the different whale species, discover how they evolved and how they eat, sleep and communicate with each other. Follow them on their long migration journeys around the world, and find out why they sing, how they look after their young, where in the world to watch them and why they urgently need our protection.