The Green Belt starts in the Small Pannonian Basin south of the Danube river and passes Lake Fertő and the surrounding hilly wine-growing district (Fertő World Heritage, Fertő-Hanság National Park). It follows the transition line between Eastern Alpine Foothills and the Pannonian Lowlands (Nature Parks Sopron Mountains and Íroettko/ Geschriebenstein) till it ends with the gentle hill region of the trinational nature park Raab – Örseg – Goricko.
The transition from suboceanic to warm continental climate of the Pannonian Lowlands along the Austro-Hungarian Green Belt provides conditions for species of both regions resulting in a very high biodiversity.
The national parks Neusiedler See/Seewinkel (Austria) and Fertö-Hansag (Hungary) consist of the steppe lake, meadows, lacken, moor areas and floodplains of the river Répce. Fertö/Lake Neusiedl is an extremely important habitat for migratory birds. On the large meadows used by birds cattle, horses and donkeys are keeping the grass short.
Sopron mountains, Rosalia and Landseer Nature Park surround the Hungarian enclave of Sopron (the citizens voted for Hungary in 1921).
The soft hilly region of southern Burgenland with its traditional cultural landscape, its streams and partly thermophile forests includes several nature parks on both sides.
Over centuries today's Austria and adjacent countries had been strongly connected by the multi-ethnic states 'Holy Roman Empire', 'Hungarian Kingdom' and 'Habsburg monarchy'. World War I led to the dissolution of the Austro-Hungarian Empire, leaving several national states.
Austria formed its first republic, the Federal State of Austria and remained militarily neutral.
During World War II Hungary was part of the Tripartite Pact until 1944 when the first and later until 1945 when the second armistice with the Soviets was signed.
After the war the socialists gained influence, until in 1949 a new constitution was passed following the soviet constitution.
While intrastate restrictions were rather strict during the stalinist era and especially during and after the Hungarian revolution 1956, the border defenses to neutral Austria after 1956 at the beginning were comparatively small with a chain link fence and watchtowers. Later the border was protected by a barbed wire fence with an arable stripe of 60 metres width on the Hungarian side, partly mined until 1965, and a service road along the border with watch towers. 2-3 km from the borderline there was a double barbed wire fence with electric alarm with a raked area of 8-10 m in between to perceive traces of fugitives. The area between the border and the double fence was called 'border-belt', where even the inhabitants could only go after applying for official permission.
The Pan-European Picnic in August 1989 and the opening of the border between Hungary and Austria in September 1989 can be seen as the first cracks in the 'Iron Curtain'.
After 1989 the big numbers of crossovers into the rich West induced Austria to control the Hungarian - Austrian border by the Federal Army. To cope with organised people smuggling the army used modern technique to reject immigrants already on the Hungarian side. But on December, 21/2007 the external Schengen Border has been moved to the eastern border, making the former Iron Curtain more permeable.