Up in the north-east, the one-day (21km) leg-stretch from Bamburgh to Craster along Northumberland's undeveloped coastline links two castles (grand Bamburgh and artfully ruined Dunstanburgh), some of the country's wildest beaches and excellent smoked kippers.

BBC: Walking Great Britain��s great coast

Roger DeClements says his Idaho-based firm, CastleMagic , has already constructed four castles and has two more in the pipeline.

FORBES: Castles For Sale

CastleMagic has built four castles so far, with two more under way.

FORBES: Castle 4 Sale