Main Street 310

The building at Hauptstraße 310 is a residential building in Königswinter, a town in the Rhein-Sieg-Kreis in North Rhine-Westphalia, that was built in 1902 as a post office. It is listed as a historical monument.
The building was developed as a so-called rental post building, constructed by a private company according to plans and specifications of the Imperial Post and rented to them long-term. On May 1, 1903, the official rooms of the post office in the new building were put into operation. It was transferred to state ownership in 1914. In the course of the separatist movement in the Rhineland in 1923, the post office was occupied by Moroccan soldiers under French command, interrupting service operations. In early August, services could be gradually resumed until armed separatists occupied the post office again temporarily on October 25, 1923.

Wikipedia