Over four seasons, Iolo Williams goes to his favourite locations in Snowdonia to look for stunning wildlife, and meets people who help him discover the national park's true nature ...

Pine martens have a long fluffy tail, prominent ears and a long face. Their brown fur is a milk chocolate colour in winter and dark chocolate colour in summer with a creamy patch of fur on their chest ...

Snowdon - Yr Wyddfa in Welsh - is the highest peak of England and Wales, in the middle of the Snowdonia National Park.