Devín Gate or Hainburger Gate is a natural gate in the Danube

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

 valley at the border of Slovakia

Slovakia

The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

 and Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

. In a wider sense it begins below Bratislava Castle

Bratislava Castle

Bratislava Castle is the main castle of Bratislava, the capital of Slovakia.The massive rectangular building with four corner towers stands on a quite isolated rocky hill of the Little Carpathians directly above the Danube river in the middle of Bratislava...

, 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

Devín Castle

Devín Castle is a castle in Devín, which is a borough of Bratislava, the capital of Slovakia....

 and ends near Hundsheimer Berg in Austria on the right bank of the Danube.

In Slovakia, the Gate is a part of the Little Carpathians

Little Carpathians

The Little Carpathians are a low, about 100 km long, mountain range, part of the Carpathian Mountains. The mountains are situated in Western Slovakia, covering the area from Bratislava to Nové Mesto nad Váhom, a very small part called Hundsheimer Berge is situated south of Devín Gate in...

.

It has been inhabited since prehistoric times and castle

Castle

A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

s have been built here, particularly the Hainburg Castle, Devín Castle, and Bratislava Castle.

Passau

Passau

Passau is a town in Lower Bavaria, Germany. It is also known as the Dreiflüssestadt or "City of Three Rivers," because the Danube is joined at Passau by the Inn from the south and the Ilz from the north....

, Devín Gate, and the Iron Gates divide the Danube river into four distinct sections.