Rosenborg Castle

Christian IV built Rosenborg between 1606 and 1634 as a summer pleasure palace, and he loved the place so much that he chose to die there. Literally — in 1648, the aging king insisted on being carried to Rosenborg for his final days, and he expired in the very rooms he had designed. The castle started as a modest two-storey summer house and grew over three decades into the Dutch Renaissance jewel you see today, with its red brick walls, sandstone ornaments, and copper-green spires rising above the King's Garden.

The crown jewels in the basement vault are the real draw. Unlike most European crown jewels, which are locked behind glass and retired, the Danish regalia is both on public display and still in active royal use. The collection includes four garnitures — diamond, ruby, pearl, and emerald sets — with the emeralds considered among the finest in the world. The pearl necklace in the Pearl-Ruby Set dates to the late 17th century and is still worn by the Danish queen on state occasions. Christian IV's crown, made in 1596, sits in a vault guarded by the same three life-size silver lions that have stood watch since 1670.

The Knights' Hall on the top floor is a masterpiece of royal intimidation. The coronation thrones are flanked by those silver lions, and the ceiling is covered in elaborate stucco work. But the strangest detail is the throne canopy supports: they are made of narwhal tusks, which in the 17th century were believed to be unicorn horns and were worth more than their weight in gold. Christian IV knew exactly what he was doing — using the rarest material on earth to frame his seat of power.

The surrounding King's Garden is Copenhagen's oldest park, laid out in the early 1600s, and today it is the most visited park in the city. In summer, Copenhageners treat the lawns like their living room.