Königsberg-Sanatorium

Königsberg-Sanatorium is a hospital ruin located on forested grounds near the Grane reservoir, comprising multiple abandoned medical buildings and support structures. The complex occupies a substantial area with various buildings in different states of disrepair and decay.

Founded in 1895 by the Hanover State Insurance Institute, this facility was Germany's first tuberculosis treatment center built through the social insurance system. The sanatorium later expanded and changed its purpose several times during the 20th century.

During the 1950s, the facility functioned as a medical resort where patients enjoyed entertainment and recreational programs as part of their healing process. This approach showed how treatment combined medical care with leisure activities.

The site currently operates as a training ground for rescue dogs and is restricted to unauthorized visitors due to structural safety concerns. Those interested in the location should check current conditions beforehand and respect the property boundaries.

A fire in June 2009 destroyed the main building and led to its immediate demolition, while additional structures sustained damage in a subsequent 2015 fire. These fires marked turning points that ended the site's use as an active facility.