On the Lancashire coast, Helen Skelton heads to Fleetwood's Rossall Coastwatch Tower, where she joins the local National Coastwatch volunteers to learn the skills needed to keep eyes on the water. JB Gill explores the cliffs of Porthcawl, South Wales, where layers of ancient limestone reveal a forgotten prehistoric world. In Dorset, Jules Hudson musters his courage for a paragliding flight above the Jurassic coast.