The Ahr Hills (German: Ahrgebirge or Ahreifel) are a range of low mountains and hills up to 623 m high and 25 kilometres (16 mi) long in the Eifel region of Germany, which lie roughly southwest of Bonn on the border between the German states of North Rhine-Westphalia and Rhineland-Palatinate.
The forested Ahr Hills have numerous tourist destinations (e. g. Aremberg Castle and the Effelsberg Radio Telescope) and the section of a Roman road with its ancient Eifel Aqueduct.
The Ahr Hills are part of the Eifel, the bulk of which lies to the south and southwest of it. It lies on the left, i.e. northwestern, bank of the river Ahr, roughly 40 km southwest of Bonn. Sometimes the ridge on the right, southeastern, bank of the Ahr in the area of Altenahr is also counted as part of the Ahr Hills. This small range is bordered by a square enclosed by the Grafschaft and Remagen to the east, by Altenahr to the southeast, Antweiler to the south, Blankenheim to the west and Bad Münstereifel and Rheinbach to the north.
To the north the terrain of the Ahr Hills descends into the Cologne Bay, to the east it drops down to the Voreifel and the valley of the Middle Rhine, to the south on the far side of the Ahr is the Eifel proper (up to 747 m), to the west the Zitter Forest and in the northwest the North Eifel.