Holyroodhouse - The Palace of Holyroodhouse, commonly referred to as Holyrood Palace, is the official residence of the monarch in Scotland. The palace stands at the bottom of the Royal Mile in Edinburgh, at the opposite end to Edinburgh Castle. Holyrood Palace is the setting for state ceremonies and official entertaining.
Holyrood Abbey was founded by David I, King of Scots in 1128, and Holyrood Palace has served as the principal residence of the Kings and Queens of Scots since the 15th century. Queen Elizabeth II spends one week in residence at Holyrood Palace at the beginning of each summer, where she carries out a range of official engagements and ceremonies.
The palace is open to the public throughout the year, except when members of the Royal Family are in residence. In modern times, monarchs have spent at least one week every year formally holding court in the palace. The present Queen spends one week at Holyrood in summer, during which time investitures are held in the gallery, audiences are held in the morning room, and garden parties are hosted. While she is in residence, the Scottish variant of the Royal Standard of the United Kingdom is flown; at all other times the Royal Standard of Scotland is displayed.
Source & More Information: Wikipedia, Holyrood Palace, http://en.wikipedia.org/wiki/Holyrood_Palace