Armed with his interwar copy of Bradshaw’s Guide to the Railways, Michael reaches the Kent seaside resort of Herne Bay, where he learns about a pioneering aviatrix who began her working life as a typist in Hull but whose epic achievements made her an international celebrity. Michael takes the train five miles west along the coast before heading offshore into the entrance to the Thames Estuary. He is amazed by seven enormous steel sea forts, which loom out of the water 90 feet above the seabed. The engineering involved in constructing these impressive structures is awe-inspiring, as is their role in protecting the nation from enemy bombing during the Second World War. In the seaside town of Whitstable, Michael tucks into its famous staple, oysters. He then crosses the North Downs to Lenham, from which he visits Leeds Castle, the 'loveliest castle in the world' and home between the wars to the visionary Lady Olive Bailey.

• Michael Portillo