The Nürburg is a ruined hilltop castle in the German Eifel Mountains near the village of Nürburg south of Adenau in the district of Ahrweiler in the state of Rhineland-Palatinate. It stands within the famous North Loop, or Nordschleife, of the Nürburgring racing course at a height of 678 metres on a volcanic basalt cone. It may be visited for a fee.