4. The Fortress in the Lake - Llangorse Lake, Powys

The Time Team travel to Brecon Beacons in Wales, they have come to investigate a small man-made island in Llangorse Lake. Locals tell many strange legends including hearing the sounds of Church bells echoing across the body of water at night. The Team want to know who built the island and try to find evidence to support the stories of it eventual fall into disuse.