 It was designed by American architect Vito Acconci and contains a café, an open-air theatre and a playground.The historic centre was added to the UNESCO World Heritage List in 1999 due to the harmonious co-existence of typical buildings from different epochs and in different architectural styles.Situated in a cultural borderland between Central Europe, Italy and the Balkan States, Graz absorbed various influences from the neighbouring regions and thus received its exceptional townscape.