London's Secret Walks is a walking book with a difference, taking in many of London's lesser-known, but no less worthy sights. As Samuel Johnson said to his friend Boswell in the 18th century, on the occasion of the latter's arrival in London: "survey its innumerable little lanes and courts." By extension, wander off the beaten tourist track and you'll discover a world of fascinating sights and attractions that not many tourists - or even Londoners - get to see.