On the corner of Castle Street and King Street stands the old North of Scotland Bank by Aberdeen born architect, Archibald Simpson. This building, with its imposing corner entrance of four giant order composite columns, and statue of Ceres above, is now a pub named after its original architect. On the opposite side of the street is the fine building of the Union Bank, redeveloped in 2005 as the High Court, the third permanent high court to sit in Scotland. At the upper end of Castlegate stands The Salvation Army Citadel, an effective castellated mansion, on the site of the medieval Aberdeen Castle. In front of it is the Mercat Cross, built in 1686 by John Montgomery, a native architect. This open-arched structure, 21 ft (6 m) in diameter and 18 ft (5 m) high, comprises a large hexagonal base from the centre of which rises a shaft with a Corinthian capital, on which is the royal unicorn. The base is highly decorated, including medallions illustrating Scottish monarchs from James I to James VII. To the east of Castle Street were the military barracks, which were demolished in 1965 and replaced with two tower blocks. Castlegate is also home to some of the oldest surviving streets in Aberdeen. Some of these are from the 13th and 14th centuries. Two houses, Provost Skene's House (1545) which is now a museum, and Provost Ross's House (1593) are in the Castlegate as well. This imposing terrace of late Victorian granite buildings is a prominent landmark in the city. Constructed in 1892, to a design by open competition winner Alexander Brown, the Central Library, which was opened by its benefactor Andrew Carnegie, stands at the west end of the terrace. Brown was also responsible for the extension to create the Central Reading Room in 1905. St Mark's Church by architect Alexander Marshall Mackenzie in the middle of the terrace has a giant order quatrostyle Corinthian portico, and dome modelled on St Paul's in London. His Majesty's Theatre by Frank Matcham, 1906, stands at the east end. Marischal College and Greyfriars Kirk on Broad Street, opened by King Edward VII in 1906, is the second largest granite building in the world (after the Escorial, Madrid), and is one of the most splendid examples of Edwardian architecture in Britain. The architect, Alexander Marshall Mackenzie, a native of Elgin, adapted his material, white granite, to the design of the building with the originality of genius.