Iolo Williams explores the wonders of Wales's country parks, starting with the magnificent Great Orme in Llandudno. It is a park full of history and ancient mines, and thousands of people visit the magnificent limestone headland every year for its fantastic views of the north Wales coast, but few visitors are aware of the special wildlife living there. Iolo meets some local experts and finds the Orme's rare moths and butterflies, ferocious stoats and migrating birds.

Nature expert Iolo Williams explores the fantastic Margam Country Park on the outskirts of Port Talbot. Once owned by one of the richest families in south Wales, it features beautiful parkland, lakes and mature woodland with three species of deer, eleven species of bats and other hidden gems.

Nature expert Iolo Williams visits Padarn Country Park near Llanberis in Snowdonia. Created on the site of an old slate quarry, the park is set in a stunning landscape surrounded by the highest mountains in Wales. Ring ouzel, one of the most sought-after birds in the whole of the UK, sing above the old slate tips, and wood warblers and pied flycatchers have established territories in the park's ancient woodland that's remarkably survived two centuries of mining. Hidden in the woodland are derelict buildings, once used to store gunpowder, and the old quarry work levels are favourite places for slow worms - our legless lizards. The trains of the old quarry have also survived and have been lovingly restored by Llanberis Lake Railway. Llyn Padarn is the second largest natural lake in the whole of Wales and is one of the prime spots in Snowdonia for water sports, but by night otters use the lake and the deep water is home to Arctic char fish.

Nature expert Iolo Williams visits Dare Valley Country Park near Aberdare, right on the edge of the Brecon Beacons. It was the first country park in Wales, and the first in Britain to be built on reclaimed land. Up until the 1960s the valley had 19 coal mines and most of the landscape would have been toxic for wildlife. Today it has been completely transformed from an industrial landscape to managed wild parkland. Dippers, herons, cormorants and kingfishers frequent the Dare River and the newly constructed lakes. The thin soil over the old coal tips attracts scarce butterflies, like the dingy skipper, and the smaller insects and ants living amongst the grassy tussocks attract lizards.