Lunchtime Tourism: Cannon Street’s blink-and-you’ll-miss-it London Stone Life&Style You wouldn’t know it, but London’s heart beats from a small alcove just opposite Cannon Street station. The city’s heart is made of limestone, wrenched from Rutland and its beats are faint. But its power is unmistakable. Passing office workers fear it so much they’re reluctant to even look at it, let alone stand near it. [...]