The ruined and recently renovated Devín Castle is in the borough of Devín, on top of a rock where the Morava River, which forms the border between Austria and Slovakia, enters the Danube. It is one of the most important Slovak archaeological sites and contains a museum dedicated to its history. Due to its strategic location, Devín Castle was a very important frontier castle of Great Moravia and the early Hungarian state. It was destroyed by Napoleon's troops in 1809. It is an important symbol of Slovak and Slavic history.