Pfalzgrafenstein Castle, Germany

This former customs post was built in the 14th century, on an island on the banks of the River Rhine, also in Germany. Whoever arrived there had to pay tolls to the owner of the land. Today, the building houses a museum.

The popular “Pfalz” is one of the few specimens of its time that survives to this day. Survived invasions, wars and floods. The highlight goes to the pentagon-shaped tower, surrounded by a hexagonal wall constituting the unusual shape of a ship. Quirky, huh?