Official seat of the CCNR and its secretariat.

The building was designed by the german architect Hermann Eggert in 1882.

It was erected between 1884 and 1888 in the neo-Renaissance style as palace of the emperor, i.e. as residence for the german emperor during his visits in the then german province Alsace-Lorraine. It was used by Emperor Wilhelm II only 5 times up to 1914 and from 1920 it has served as "Palais du Rhin", the residence of the CCNR.