Poundbury is an experimental urban extension on the western outskirts of Dorchester in the county of Dorset, England. The development is led by the Duchy of Cornwall, and had the keen endorsement of King Charles III when he was Prince of Wales and Duke of Cornwall. Under the direction of its lead architect and planner Léon Krier, its design is based on traditiā¦Poundbury is an experimental urban extension on the western outskirts of Dorchester in the county of Dorset, England. The development is led by the Duchy of Cornwall, and had the keen endorsement of King Charles III when he was Prince of Wales and Duke of Cornwall. Under the direction of its lead architect and planner Léon Krier, its design is based on traditional architecture and New Urbanist philosophy. The 2021 census showed a population of 4,100.