To prevent people migrating from Hungary to Yugoslavia and perhaps further West, this border was heavily guarded, mined and protected by electric fence. The regime somewhat softened after Stalin's death, but the border remained guarded until the countries entered Schengen in 2007. Reading the information at one of the crossings (see another highlight) and following the path along the border gives some impression of the iron curtain and the measures that the governments in the Soviet block needed to take to prevent their citizens from escaping the communist "paradise on Earth". :)