Demand in cities for locally sourced food is growing, but space is at a premium. La Caverne is housed within 9,000 sq m of a disused multistorey parking facility beneath a social housing complex in Paris. Since 2017, Jean-Noël Gertz, a thermal engineer and founder of agricultural start-up Cycloponics has used this space to grow mushrooms and endives and deliver them to the organic shops of the city’s inner north. A conveyor belt runs across several numbered parking bays, along which staff separate endives from their gnarly roots and pack them into crates for delivery. Endives, grown entirely without sunlight, are a perfect crop for a below-ground venture like this and are now the fourth most popular vegetable in France.