Grand Designs: East Devon, 2013

Kevin McCloud meets a master craftsman whose dream is to build a castle in rural Devon made entirely of mud. Kevin McCabe plans to form the huge property out of two vast curved roundhouses - the largest of which is inspired by the natural geometry of a snail shell - connected by glazing and topped with wildflower meadow roofs to mirror the surrounding countryside. However, the project involves mixing and laying a mind-boggling 2,000 tons of cob, all during warm, sunny weather - and the sheer scale of the task soon becomes clear