The World Heritage Site Discovery Days Festival is the biggest annual event in the Derwent Valley Mills calendar. Held each year during the October half-term school break, it encompasses nine days crammed with over 100 activities which allow people to enjoy the World Heritage Site in unusual, entertaining and informative ways. Each year, the organisers ensure there’s a host of new activities and events for a wide range of ages and interests, so the programme stays fresh and enjoyable, year after year. Launched in 2005, the Derwent Valley Mills World Heritage Site’s Discovery Days have steadily grown from one to nine days with many activities free to enter.