Having grown up with seafaring legs and a desire to explore, Caroline is both a knowledgeable guide to the most hidden-away parts of this overlooked and unfashionable part of the country, and a persuasive advocate for its significance, both historically and culturally. As one of the key entrances and exits to England, the estuary has been pivotal to London's economic fortunes and in defining its place in the world. It has also been the entry point for immigrants for generations, yet it has an ambivalent relationship with newcomers, and UKIP's popularity in the area is on the rise. As Caroline navigates the waters of the estuary, she also seeks out its stories: empty warehouses and arsenals; the Thames barrier, which guards the safety of Londoners more precariously than we might; ship wrecks still inhabited by the ghosts of the drowned; vast Victorian pumping stations which continue to carry away the capital's sewage; the river banks, layered with archaeological Anglo-Saxon treasures; literature inspired by its landscape; beacons used for centuries to guide boats through the dark and murky waterways of the estuary; the eerie Maunsell army forts - 24 metre high towers of concrete and steel which were built on concealed sandbanks at the far reaches of the estuary during the Second World War and designed to spot (and shoot) at incoming enemy planes; and the estuary's wildlife and shifting tidal moods.

    We'll learn why Thomas Hardy was buried twice, how a librarian in Manchester invented the thesaurus as a means of coping with depression, and why Agatha Christie was investigated by MI5 during the Second World War. The map of Britain that emerges is one dotted with interesting literary stories and bookish curiosities.