This week Adam Walton visits Anglesey to discuss the island's rich and varied geological history.

Showing Adam some of the geological wonders of Anglesey is Dr Margaret Wood, the director of GeoMôn, the Anglesey Geo Park. In 2009 Anglesey became the first island in the world to be designated a Geo Park. joining the ranks of UNESCO's worldwide network of sites. The Geo Park programme is designed to promote and conserve the planet's geological heritage.

The programme visits Llanbadrig overlooking Cemaes Bay, where some of the oldest fossils in the UK were discovered by Margaret Wood in the 1970s. These cyanobacteria played a vital role in creating the oxygen rich atmosphere of the Earth.

Also there's a visit to Llanddwyn Island, the tidal island at the south west corner of Anglesey, and former retreat of St Dwynwen, the Welsh patron saint of lovers. Here the programme discusses some of the rare pillow lavas that can be found there and how the island is a mini tectonic plate.

Adam also meets Mike Roberts, a PhD student at Bangor University who has examined sediment cores taken in the Menai Strait and from these has determined when Anglesey became separated from the mainland.