Graz Airport camp, run by the governments of Franz Joseph I of Austria and Charles I of Austria. The first domestic passenger flight in Austria in 1925 serviced the route Vienna–Graz–Klagenfurt. In 1930 Yugoslav flag-carrier Aeroput introduced regular flights linking Yugoslav capital Belgrade with Vienna with stops in Zagreb and Graz. In 1937, the construction of a terminal building began due to increase in the number of passengers. After the end of the Second World War, however, Austria was forbidden to possess an aviation fleet, neither military nor civil. After reopening of Austrian airspace in 1951, a new concrete runway of was
Schlossberg (Graz) ruined bastions is the "Kasemattenbühne", an open-air stage for concerts and performances. Below the Schlossberg hill is an extensive system of tunnels, which were created during the second world war to protect the civilian population of Graz from aerial bombing. Some of these tunnels are still accessible, including a passage from Schlossbergplatz to Karmeliterplatz, and a grotto railway for children. Also in the tunnel complex is the "Dom im Berg", which was expanded in 2000 to provide a venue space for up to 600 people. The summit of the hill is linked to the city centre by various steep paths