People walking the busy streets of London's southwest Chapham district probably have no idea there's a whole micro-green world thriving 100 feet below them. Once a bomb shelter that kept up to 8,000 people out of harm's way during World War II, the giant space is now the world's largest underground hydroponic (a growing method that uses water or other base instead of soil) garden.
Most of us probably wouldn't find the long tunnels of an abandoned bomb shelter all that inspiring, but for entrepreneurs and childhood friends Richard Ballard and Steven Dring, seeing the underground space was their light-bulb moment. Because, naturally, what else would you think to do with a large, sunless, concrete cavern other than start a garden?
Take a look inside the brilliant underground-bomb-shelter-turned-super-sustainable-farm below.