Jellyfish Barge (JFB) is a revolutionary solution for Urban Agriculture as it produces food without bearing on existing resources. A module produces 1400-1600 edible plants per month, grown in high efficient hydroponics. Water needed is extracted from the body of water where the greenhouse floats, whether salt or polluted water. All the need for energy is fulfilled by sun power. Thus, JFB doesn't impact on existing land, water and energy resources of the city, but expands the capacity of the urban environment to provide jobs, economic opportunities, social relations and urban quality. It combines a production facility with a vibrant public space, where creating public activities such as a weekly market. Various modules can create an agricultural archipelago activating unused docks, underutilized waterfronts areas and forgotten spots in the city and making them productive, letting production of food move to the place of consumption while starting a urban regenerative process.