"London is full of curiosities. Who knew that beneath the Albert Memorial lies an undercroft resembling a church crypt? Or that there are catacombs under Camden? Who would expect to find a lighthouse in East London, sphinxes in South London, dummy houses in West London, or a huge bust of film director Alfred Hitchcock in North London? How many of those who walk past Cleopatra's Needle pause to consider why a 3,000-year-old Egyptian monument stands...