The One Show comes live from the beach at Weston-super-Mare for the first One Show Summer Festival. Rhod Gilbert joins Matt Baker and Alex Jones for plenty of sun, sea and sand. Marty Jopson reveals the science of sand castles, Mike Dilger braves a colony of seagulls, Larry Lamb heads to Normandy to learn about the mad piper and Justin Rowlatt keeps the crowd entertained with a knobbly knees contest or two.