French start-up is using hydroponic techniques to bring organic farming into abandoned urban areas.

Something is growing under the streets of Paris. An underground farm has been built beneath an old car park in La Chapelle, a neighbourhood in the north of Paris. The farm, by Cycloponics, an indoor farming startup, will grow lettuces, herbs and mushrooms using hydroponic techniques in which the plants are grown in nutrient-rich water under low-energy LED lights, without the use of soil or natural sunlight. The 3,600 square foot farm, called La Caverne, has already begun producing oyster, shiitake and Paris mushrooms, and will begin endive production next. Produce will be sold to markets and restaurants and delivered by bike.
Link: https://www.springwise.com/startup-launches-fully-organic-underground-farm-paris/