Kronborg Castle is one of the national symbols of Denmark and probably the most famous castle in Northern Europe. It stands guard over the Öresund and was notorious for the Sound Tolls it collected from all ships entering the Baltic Sea. Today it is a major tourist attraction and an easy train ride away from Copenhagen. Combined with a ferry ride over to Sweden and a visit to Malmö (followed by a train ride over the Öresund Bridge), it makes a great day trip. The castle has many historic features, including a chapel and very dark underground corridors with a statue of Holger Danske, and there is an interesting maritime museum, for which a new building is due to open in 2013 outside the castle. I found Kronborg very interesting, but somehow I suspect that it would not have made the WH list without its association to Shakespeare and Hamlet.