Kronborg Castle, Helsingør

A Renaissance castle on the narrowest point of the Øresund strait, where Danish kings collected tolls from passing ships. It's best known as Elsinore, the setting of Shakespeare's Hamlet; plays are performed here in summer. It's a UNESCO World Heritage Site.

Explore the royal apartments, the ballroom and the dark casemates, where the statue of the sleeping hero Holger Danske waits. The Maritime Museum of Denmark is built underground nearby. It's 45 minutes by train from Copenhagen.