Puerta del Sol is the main public setting for Madrid's televised New Year's Eve countdown.
The central Madrid square is known for the clock on the Real Casa de Correos, the former post office building that now houses the presidency of the Community of Madrid. On December 31, the clock's midnight chimes are broadcast nationally, and people traditionally eat twelve grapes in time with them.
Puerta del Sol is one of Madrid's most important civic spaces. It contains the famous statue of the Bear and the Strawberry Tree, a symbol associated with the city, and it is near the kilometer-zero marker used for Spain's radial roads. Those landmarks are separate from the New Year's clock, but they help explain the square's national visibility.
The midnight broadcast is sometimes described as occurring in “Madrid” without naming the square. The precise location matters because celebrations elsewhere in Spain may use local clocks and gatherings, while Puerta del Sol supplies the best-known shared televised countdown.