Holtorfer Hardt

Overlooking the rooftops of Bonn, the Holtorfer Hardt stands sentinel. It whispers tales of industry and nature. The Holtorfer Hardt isn’t just a hill. It’s a northeastern rise of the Ennert ridge. It reaches a height of 150.8 meters above sea level. The Holtorfer Hardt is also known as the Ennert-Hardt. This distinguishes it from the Dollendorfer Hardt and another Hardt further south. Today, the Pützchens Chaussee and Oberkasseler Straße cross the Holtorfer Hardt. Here you can find the Hardtweiher pond. There’s also a research center for hunting with a game reserve. You can enjoy a viewpoint and a hiking hut. On the eastern slope lies Niederholtorf. The Alaunbach and Teufelsbach streams flow north from the Holtorfer Hardt. The Ankerbach flows south. To the south lies the Röckesberg. To the west rises the Ennert itself, which gives the ridge its name. Northeast lies the Holzlarer See, fed by the Holtorfer Bach. Long ago, around 1800, brown coal mining thrived in the Ennert and the hilly area to the east. In 1807, Leopold Bleibtreu discovered a lower coal seam. This seam was about 1.5 meters thick and contained pyrite and clay. He realized the potential for alum production. Subsequently, these seams were mined. The coal was processed into alum at two alum huts on the Holtorfer Hardt. These huts belonged to the Bleibtreu family and entrepreneur Matthias Jäger. From 1835, underground mining began. In 1853, Bleibtreu and Jäger merged to form the Bonner Bergwerks- und Hütten-Verein Aktiengesellschaft. Their Bonn cement factory sourced raw materials from the Holtorfer Hardt. By 1863, production declined. Cheaper methods for alum production had been developed elsewhere. Mining ceased entirely in 1876. The alum huts were largely demolished. Their stones were used for the first church in Niederholtorf, which has since been replaced. Three burial mounds were also discovered on the western slope of the Holtorfer Hardt. This whispers of even older stories hidden within the earth. The Holtorfer Hardt stands as a testament to Bonn’s industrial past. It offers a peaceful retreat into nature.