The Victoria Tower is a square tower at the south-west end of the Palace of Westminster in London, adjacent to Black Rod's Garden on the west and Old Palace Yard on the east. At , it is slightly taller than the Elizabeth Tower (formerly known as the Clock Tower and popularly known as 'Big Ben') at the north end of the Palace (). At the time of its construction it was the tallest square tower in the world. It was designed by Charles Barry in the Perpendicular Gothic style and was completed in 1860. It houses the Parliamentary Archives in archive conditions meeting the BS 5454 standard, on 12 floors. All 14 floors of the building were originally linked via a single wrought-iron Victorian staircase of 553 steps, of which five floors survive. The steps are made of granite quarried from Cairngall in Aberdeenshire. The main entrance at the base of the tower is the Sovereign's Entrance, through which the Monarch passes at the State Opening of Parliament. On top of the Victoria Tower is an iron flagstaff from which flies the Union Flag or, when the Sovereign is present in the Palace, the Royal Standard. The flag used to be flown only on days when either House of Parliament sat, but since January 2010 it has been flown every day. History The Victoria Tower was purpose-built as a "fireproof repository for books and documents", as required by the competition to rebuild the Palace of Westminster after the fire of 16 October 1834, which had destroyed the building and almost all of the records of the House of Commons. The records of the House of Lords survived the conflagration because they were, at the time, stored in the Jewel Tower, which was at a distance from the main building and still stands across the road from the Victoria Tower. Sir Charles Barry's design for the new Palace of Westminster featured a tower over the Sovereign's Entrance, 12 floors of which incorporated record storage. Augustus Pugin produced most of the architectural designs and elevations for the project and also the interior design. The first stone of the Tower was laid by Queen Victoria on 22 December 1843, and construction was completed in 1860. The tower was originally named "The King's Tower" because the fire of 1834 that destroyed the old Palace of Westminster occurred during the reign of King William IV.