Following the Second World War, the Croatian city of Zadar underwent a large, rapid reconstructive transformation. The city's seafront became nothing more than a concrete wall until 2005, when architect Nikola Bašić proposed to redesign parts of the seawall to interact with the ocean waves. Concealed beneath marble blocks, the 'Sea Organ' (morske orgulje in Croatian) is comprised of a network of polyethylene tubes and resonating cavities which sing as the waves and wind lap the shore. With thirty five individual pipes spanning a total length of seventy metres, it is the largest aerophone in the world. According to reports, the sound is specifically directed out to sea and is impossible to hear from within the city of Zadar itself. In 2006, the intervention was jointly awarded the European Prize for Urban Space.