In this new series, Iolo Williams delves into the archives to see the fantastic wildlife that he's filmed in Wales during the past 25 years. He also explores the changes he's seen in Welsh wildlife in that time. It all began for Iolo back in 1996 when he was still working as a warden for the RSPB. He was filmed for the series Visions of Snowdonia, tramping a remote moor looking for the nest of his favourite bird, the hen harrier. Since then, he has made many series for BBC Wales.