As the journey continues through France to Britain, meet the world's largest squirrel, an unusual blonde hedgehog, and some lost birds.
Scotland and Iceland are home to breathtaking landscapes, beavers and fish which thrive near volcanic vents.
Passing through ten countries, the Danube is the most international river in the world and connects a succession of spectacular landscapes.
As the Danube flows through its various landscapes, it transforms. Floods and drought also affect life on the great river.