Whitehall is the main avenue running from the north of Parliament Square to the southern end of Trafalgar Square. Whitehall contains many of the country’s government ministries. For this reason, it is where most public demonstrations or official parades are held in London. It is also the location of the Whitehall Theatre, built in the 17th century with Art Deco style interiors although the current building dates from 1930. Whitehall is also the location of the Horse Guards, the headquarters of the British Army.