Kronborg Castle is a magnificent Renaissance fortress standing guard at the narrowest point of the Øresund strait between Denmark and Sweden, and is immortalized worldwide as Elsinore, the setting of Shakespeare’s Hamlet. Built in the 1420s and dramatically expanded by King Frederick II in the 1580s into one of northern Europe’s finest Renaissance castles, this UNESCO World Heritage Site has served as a royal residence, military garrison, and customs collection point, where ships passing through the strait were taxed for centuries.

The grand Knights’ Hall, one of the longest in northern Europe at 62 meters, and the dimly lit casemates — underground passages where the legendary Viking chieftain Holger Danske sits sleeping in stone, said to awaken if Denmark is ever in peril — are particular highlights. Every summer, the castle courtyard hosts performances of Hamlet and other Shakespeare plays, continuing a tradition that dates back to 1816.

Pro tip: Take the train from Copenhagen to Helsingør (about 45 minutes) and walk along the harbor to the castle for a pleasant approach. Combine your visit with a quick ferry ride across to Helsingborg, Sweden — the crossing takes just 20 minutes, giving you two countries in one day. Do not miss the atmospheric casemates beneath the castle, where Holger Danske’s statue waits in the darkness.