The oldest building located on Puerta del Sol is the House of the Royal Post Office, built by order of Charles III in 1768. Incidentally, it is his monument that stands in the center of the square, facing the structure erected at his command.
They say that in order to create such a majestic building on what were then the still narrow streets of the old city, two nearby blocks had to be demolished and a new street laid out - Calle de Postas, intended precisely for the movement of mail coaches.
Today, this building houses the government of the province of Madrid. But among the people it is more famous for other reasons. Take note of the clock tower on the roof of the building - on New Year's Eve all of Spain watches these chimes, traditionally making a wish, eating 12 grapes, and washing them down with Spanish sparkling wine Cava.
On the pavement in front of the House of the Royal Post Office, you can find a plaque marking Kilometer Zero - the official starting point of six Spanish roads. By standing on it, you can make a wish at any time of day or night, and there is absolutely no need to wait for the New Year ;)
