The Digital Water Pavilion is a singular and innovative project of Milla Digital, implemented by Expoagua Zaragoza 2008 on behalf of the City of Zaragoza. Located in the connection node of the Expo site with the Milla Digital area, the DWP joins the theme of water with the digital technologies, creating a sense of continuity towards the future for the big projects of transformation nowadays in course in Zaragoza. This Pavilion of minimalist expression and small dimensions is, at the same time: a sophisticated machine of high mechanical precision; a building appearing and desappearing thanks to a 12 hydraulic pistons system; and a place where spaces are flexible, changing and responsive due to the action of 120 meters of water walls digitally controlled by almost 3.000 electromagnetique valves. It has been designed by Carlo Ratti Associati, developping the interactive water wall concept created by the Smart Cities Group (MIT Media Laboratory) with the direction of Prof. William J. Mitchell.