My trips to various cities have provided me with another perspective on history.
I visited Potsdam, which was the residency of the royalty of Prussia. It has impressive architecture with many castles in different styles. One of the castles, Cecilienhof, was built in built after an example of "Jagdschloss Gelbensande", which I have visited some years earlier. I visited Sanssouci palace - which was built by Frederick the Great of Prussia - and its park, which was fascinating. Actually, the ruins you see in one of the photographs from the park of Sans-Soucis are not really ruins, they are just made out to be ruins because it was fashionable at that time.
Additionally, I visited a megalithic tomb - a dolmen in Drente, the Netherlands.