Haus Attenbach, Architectural heritage monument in Hennef, Germany.

Haus Attenbach is a two-storey former noble residence on the left bank of the Sieg in Hennef, built in 1545 on the site of a late medieval complex. Its two round corner towers place it among the lowland castles, and above the entrance door a date and the double coat of arms Gevertzhagen-Vünfzahl are set into the lintel. The building is privately owned and can only be viewed from outside.

The property appears in monastery records from 1142, and Knight Johann von Attenbach made it his residence around 1367. The current building was constructed around 1545, replacing earlier fortifications at this strategic location along the Sieg.

The manor reflects how military design and residential comfort merged during a period when such transitions shaped local nobility. The visible round towers and their placement show how people balanced defensive needs with everyday living.

Haus Attenbach stands on the left bank of the Sieg in Hennef, in the hamlet of Greuelsiefen. It is in private ownership, so the two-storey house with its two round corner towers can be viewed only from outside. Visitors approach on foot or by car and look at the stone walls, the steep tiled roof with its dormers and the tall brick chimney from the public way.

Baron Theodor von Hallberg-Broich took over the estate in 1810 and became one of the wealthiest individuals in the region within a few years. His family's influence on local history is often overlooked when visitors focus only on the building's architecture.