 15-minute cities are basically where bigger cities are divided up into smaller sections or neighbourhoods. Everything people need, like shops, gyms and bars, are all within a 15-minute walk or cycle. The idea of 15-minute cities has spread to Paris, Melbourne and South Korea, attracted by the promise of lower car use and a better quality of life. Actually, it doesn't have to be technology. It's just bringing a revolutionary lens to the assets that we have right now.