The return of the Siegesburg: 3D-reconstruction of a disappeared and forgotten monument

Many Cultural Heritage (CH) monuments are destroyed in the past and they are often lost forever. If there is no contemporary metric documentation of the historic objects available, the monument and the information about this monument could be disappeared and forgotten forever. The Siegesburg (also known as Segeberg castle) located on the "Kalkberg" (Chalk Mountain) in Bad Segeberg in Northern Germany, is a typical example for such a monument, which was destroyed by Swedish troops at the end of the Thirty Years' War in 1644. This important monument was only documented by a few historic isometric maps, but the castle and even the later castle ruin were totally destructed and demolished over the last centuries and disappeared forever. Furthermore, this significant memorial is even forgotten in many people's mind.
This contribution describes the physical and virtual return of the Siegesburg by 3D reconstruction using historic sources. The laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg conducted this project in co-operation with the museum Alt-Segeberger Bürgerhaus (Old-Segeberg town house). The process of the 3D reconstruction and visualisation of both the Kalkberg and the castle is presented in this paper.