London’s Alleys: Grotto Passage, W1

In the heart of Marylebone, a narrow gap between rows of upmarket shops leads to an alley that was once a notorious slum.The slums were built on the site of an actual grotto — an early tourist attraction built by John Castles in what was still countryside along the newly built Paddington Street. The grotto opened in 1738 and quickly became a fashionable place to visit to admire the shell-lined covered tunnels. John Castles built a second grotto in 1756, turning the original into a dining s