Iolo visited moor land above Lake Vyrnwy in the heart of the Berwyn Mountains, where the hen harrier and merlin hunt and nest and New Grove Meadow near Monmouth, where there is a fabulous old hay meadow full of rare orchids. Croes Robert Woodland near Monmouth, has one of Wales' rarest species - the dormouse.

• Moorland and hen harriers

The Deeside estuary has extensive areas of mud flat, sand flat and large areas of salt marsh. Little terns return every year to nest at Gronant. Natterjack toads were extinct in Wales. The dunes at Talacre are the only site in Wales where you can find them. Watch a video clip of the dunes. Hillbre Island off the Wirral is an important place for migrating birds. The Gwent Levels in South East Wales have been re-claimed from industry and farmland. They are rich in water birds including the exotic little egret, and numerous moth species.

• Counting birds at the Deeside estuary

We filmed one of the first sightings in Mid Wales of the Great Egret as well as yellow wagtails, courting hares, sand martins and sedge warblers. For three months every summer, thousands of sea birds return to the rocky cliffs of South Stack Anglesey - including guillemots and razorbills. Resident nesting peregrines have taken full advantage of the sea cliffs give. Malltraeth Marsh is in the heart of Anglesey on land reclaimed from farmland, fashioned to attract the rare bittern.

The highlands of Scotland is a journey into the past. Species include golden eagles, osprey, short-eared owls, black-throated divers, and the pine marten.

The Wildfowl and Wetlands reserve at Penclacwydd near Llanelli is a reserve re-claimed from industry. Today it's a haven for species including a range of waterfowl, water vole, moorhen and dragonflies.

• About the reserve and water voles

The island of Skomer off the Pembrokeshire coast is home to thousands of auks including puffins - one of the most important sites for this species in Britain. There are also thousands of manx shearwaters, who fly from South America to Skomer each year to breed. Beneath the waves is Skomer Marine Nature Reserve.

• Skomer Marine Nature Reserve