The cargo railway hub and the international airport Pleso were built south of the Sava river. The largest industrial zone (Žitnjak) in the south-eastern part of the city represents an extension of the industrial zones on the eastern outskirts of the city, between the Sava and the Prigorje region. Zagreb also hosted the Summer Universiade in 1987. This event initiated the creation of pedestrian-only zones in the city centre and numerous new sport infrastructure, lacking until then, all around the city.