The national opera house of Denmark, Operaen or the Copenhagen Opera House, is ranked among the most modern opera houses in the world. It is also one of the most expensive opera houses ever built with construction costs well over 500 million U.S. dollars. The opera house is built in alignment with Amalienborg and The Marble Church, so that if one stands in the main entrance of the Opera, one can see the Marble Church over the water along the road through Amalienborg.