Devín Gate or Hainburger Gate (Hungarian: Dévényi kapu, Slovak: Devínska brána, formerly Latin: Porta Hungarica in Austria Hainburger Pforte ) is a natural gate in the Danube valley at the border of Slovakia and Austria, part of the Devín Carpathians mountain range. Passau, Devín Gate, and the Iron Gates divide the Danube river into four distinct sections.
In a wider sense it begins below Bratislava Castle, in which case the gate is 11.5 km long and 2 to 7 km wide; in a narrower sense it begins below Devín Castle and ends near Hundsheimer Berg in Austria on the right bank of the Danube. It has been inhabited since prehistoric times and castles have been built here, particularly the Hainburg Castle, Devín Castle, and Bratislava Castle.