The Hirschburg is a historic country villa with castle character in Königswinter, a town in the North Rhine-Westphalian Rhein-Sieg district, which was built in 1883/84. It lies on the north-west slope of the Hirschberg (257 m above NHN) in the Siebengebirge, east of and above the Nachtigallental. The Hirschburg is a listed building.
The owner of the property was Jacob Anton Biesenbach, brother-in-law of Baron von Sarter, for whom Biesenbach had previously built the Drachenburg Castle on the other side of the Nightingale Valley. The Hirschburg took over its neo-Gothic stylistic elements from this. The architects Gerhard Franz Langenberg and Wilhelm Hoffmann worked on the design. In 1893, the associated park and forest area was fenced in with a wall on the road side and partly also on the mountain side. After Biesenbach's death in 1899, the Hirschburg came into the possession of the von Malinckrodt family from Cologne. In April 1910 it was sold for 375,000 marks to the Cologne wagon manufacturer Paul Charlier, who then had it renovated and especially redesigned on the south side.
In 1933 the Hirschburg was acquired by the Mannesmannröhren-Werke. Initially, it was planned to be used as a home for mothers and children, but from 1943 it was initially used as the company's administration building. From March 1950 it served as a convalescent home for Mannesmann employees. In 1958 a gymnastics hall was built in the form of a rotunda in the southern part of the park, which was later followed by a sauna and a plunge pool. In 1971/72 a new guest house was built below the Hirschburg. In 1992, the Roermond earthquake caused damage that required renovation work to be carried out on the building. Mannesmann decided to set up a seminar and conference center in the Hirschburg. The entry of the Hirschburg in the monument list of the city of Königswinter took place on September 29, 1995.
After the company was taken over by Vodafone, the Hirschburg was renovated under the direction of Michael Deisenroth in 2001/2002 and has also been used by the new owner, including the surrounding buildings, as a conference venue since 2003.