Hennef (Sieg) is a town in the Rhein-Sieg district of North Rhine-Westphalia, Germany. It is situated on the river Sieg, approx. 7 km south-east of Siegburg and 15 km east of Bonn. Hennef is the fourth-biggest town in the Rhein-Sieg-Kreis (i.e. district). It is the site of the 15th-century castle, Schloss Allner, next to the Allner See. Within Hennef is the town of Stadt Blankenberg, with the castle of Blankenberg.

Villages in Hennef

Hennef is known as the "City of 100 villages". The official list counts 89.

List of villages with number of inhabitants in 2024.

Twin towns – sister cities

Hennef is twinned with:

Trivia

Notable people