The Puerta del Sol (Sun Gate) is known as 'Spain's belly button'. In the 1400s, it was the gate or entrance of the east side of the city. Since the sun rises in the east, it got the name Puerta del Sol. It is now the center of 'kilometer 0' of Madrid. All roads are measured from this point.
It was rebuilt in 1854. The statue of King Carlos III is in the middle of the square. The red brick building there is the former post office. The famous Oso y el Madroño (bear eating madroños) statue can also be found here. The Puerta del Sol is also famous for its New Year's celebration which has been broadcast on television since December 31, 1962.