The Fortress can be visited
Fortress Strasbourg-Fort II Moltke (Rapp)
The Fortress Strasbourg-Fort II Moltke (Rapp) is located in Reichstett, in the French department of Bas-Rhin in the Grand Est region. Originally built as part of the defensive ring around Strasbourg, it is now an accessible example of Prussian fortress construction.
History+
Construction of the fortress began in 1872 by Prussia after the Franco-Prussian War, and it was put into service in 1874 to protect Strasbourg. Field Marshal von Moltke initiated this construction project, which was designed according to the Biehler system. After 1918, when Alsace became French again, the fortress was renamed Fort Rapp, after General Rapp, who hailed from Colmar. The facility, capable of accommodating a garrison of 800 men, remained undamaged during both World Wars. In World War I, it served as a depot and prisoner-of-war camp. In World War II, it was integrated into the Maginot Line and later used by the Wehrmacht as a depot.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://en.wikipedia.org/wiki/File:Fort_Rapp_entrance.JPG
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 48.6402, 7.7564