Clock above the Horse Guards, London
William Kent, George II’s chief architect, designed this long, picturesque building as the headquarters of the king’s military General Staff. It replaced a similar dilapidated structure dating from Charles II’s time, which had been built on the site of Henry VIII’s tiltyard. Begun in 1750, the building was completed in 1758 by John Vardy. The two mounted sentries within the archway change duty every 2 hours and are drawn from the Cavalry Regiments of the Household Division, which protects the sovereign (the Life Guards).