Palais Thurn und Taxis

When the noble Thurn and Taxis family settled in Frankfurt am Main in the first half of the 18th century, a suitable building was needed. Construction of the Thurn and Taxis Palace began in 1731. Three years later, the shell was completed and in 1739 it was ready for occupancy. As early as 1737, Prince Anselm, who kept coming to Frankfurt, moved into an apartment in the new building. After completion and the death of the prince, his son moved his residence to the palace.
After the family moved their residence to Regensburg in Bavaria in 1748, the palace remained the seat of the General Post Office until 1867. During the Seven Years' War, French troops occupied the city of Frankfurt in 1759 and set up their headquarters in the palace. After the French withdrew in 1762, the palace had to be renovated, which took around two years.
In 1789, a major renovation took place because the Crown Prince Karl Alexander von Thurn und Taxis married and wanted to live in the palace with his wife. In 1813, the palace became a federal palace. The Free City of Frankfurt made the building the seat of the Bundestag and paid the Prince of Thurn und Taxis an annual rent for it. However, the Prussian-Austrian War in 1866 brought the end of the Free City of Frankfurt.The palace remained in the possession of the royal family, who occasionally held exhibitions in the building before selling it to the Imperial Post Office in 1895. This guest appearance only lasted ten years, however, before the city of Frankfurt bought the palace and opened an ethnological museum three years later. The Second World War then caused severe damage, which led to the building being demolished in 1951. Only the portal structures were rebuilt.

Interesting if you are interested in the history of Frankfurt and Germany.