Welcome to the absolute center of London. You are standing in Trafalgar Square, a place that has served as the city’s beating heart since it was completed in eighteen-forty-four. Take a moment to look around. To your north, the grand neoclassical facade of the National Gallery watches over the space. This square is more than just a tourist photo-op; it is London's official point of measurement. If you see a road sign anywhere in the United Kingdom telling you how many miles you are from London, they are calculating the distance from the nearby Charing Cross. For over a century, this has been the site of national celebrations, political protests, and the famous New Year's Eve countdown.