The Royal Palace in Stockholm, Sweden
The Royal Palace (Kungliga Slottet in Swedish) was built between 1697 and 1754 on the site was previously a fortress built by Birger Jarl in the 13th century. Being the official residence of the King of Sweden, it is the world’s biggest palace that is still used by the head of the country. It also functions as the setting for most of the official receptions of the monarchy.
Designed by Nicodemus Tessin the Younger and completed by his son K. G. Tessin, this building has 609 rooms in seven floors. In addition to the Royal Apartments, it contains the Hall of State, the Apartments of the Orders of Chivalry, the Treasury, the Tre Kronor Palace Museum, the Armoury and the Museum of Antiquities of Gustav III.
While visiting the Royal Palace, one may find it interesting to see the changing of the guard. The event lasts 40 minutes and is free to watch.