Marksburg Castle was first mentioned in 1231, but already existed before. It is the prototype of an knights castle and became an example for a lot of phantasy castles.
Arenfels Castle, near Bad Hönningen, was rebuilt in neo-gothic style between 1845 and 1855 based on the foundation walls of the medieval castle. Because of its 365 windows, 52 doors and 12 towers it got called ''year castle''.
Worms Cathedral is the smallest of the three ''rheinischen Kaiserdome''. The two others are located in Mainz and Speyer. The Cathedral was built between 1130 and 1181.