Best Devon Attractions Best Devon Attractions Dartmoor An ancient landscape of stunning views and awe inspiring granite tors. Greenway The captivating summer home of crime writer Agatha Christie. Crealy Adventure Park Over 60 rides and attractions make Crealy one of the best family days out in Devon. Powderham Castle Powderham Castle is a 600 year old fortified manor house. National Marine Aquarium The UK’s biggest aquarium and showcases a fascinating underwater world. South Devon Railway A popular attraction, and the longest established steam railway in the south west.