A palace is a grand residence fit for a king or queen, and palaces can be found from Mexico to Indonesia. However, many royal palaces have evolved to other uses, serving as parliaments, museums, hotels or even office buildings. The few that are still occupied by royal residents offer a rare opportunity for a glimpse at the royal life. Buckingham Palace in London is both the residence and the office of Queen Elizabeth. The palace is open to the public for a few months each summer â€“ this year, from July 23 to October 3. While not all 775 rooms are open to tourists, 19 richly appointed State Rooms are. These include the Grand Hall, the Throne Room and other rooms decorated with priceless treasures from the Royal Collection of Art. In Madrid, the Palacio Real is the official residence of King Juan Carlos, though the royal family chooses to live in the more modest Palacio de la Zarzuela. The Palacio Real is used for state ceremonies, and much of it is open to the public. This palace houses great works by Spanish artists such as Caravaggio, Goya and Velasquez. Free entry is offered every Wednesday. Amalienborg Palace in Copenhagen is made up of four identical Danish Rococco buildings set around a courtyard. One of them, Christian IXâ€™s Palace, is the residence of Queen Margarethe. Two others are open to the public: Christian VIIâ€™s Palace, where the Queen receives official visitors, and Christian VIIIâ€™s Palace, a royal museum. The Throne Room and Royal Reception Rooms are located at nearby Christiansborg Palace, which is also open to the public. This is the third Christiansborg Palace on the site, having been rebuilt after a fire in 1884. While the royal family has never lived in this reconstructed Danish masterpiece, the palace also serves as home to the Danish Parliament and Supreme Court. Thailandâ€™s King Bhumibol Adulyadej prefers to live at Chitralada Palace, but the gorgeous Grand Palace in Bangkok has served as the official residence of Thai royalty since 1785. The palace complex includes several impressive buildings, including the Temple of the Emerald Buddha, one of the most visited sites in Bangkok. Even though the United States has never had a king or queen, there is a royal palace on U.S. soil: â€˜Iolani Palace, which was the official residence of Hawaiiâ€™s monarchy, which was overthrown in 1893. Located in downtown Honolulu, the palace has been meticulously restored. To find out more about visiting the worldâ€™s royal palaces, talk with your travel professional.