Puerta del Sol is one of the most emblematic places in Madrid. Because it is the historical center of the city and of the country, since it is indeed the "kilometer 0" of all national roads in Spain, and because it is a place with history, past and present.
It is one of the common meeting points for young people in Madrid, it is one of the best located places when you have to go shopping in the center and it is also known for the very famous New Year's Eve celebrations. Puerta del Sol is a must-see for all visitors of Madrid, despite the hustle and bustle, I highly recommend it.
In the last years, the authorities have tried, with relative success, to clear the area limiting traffic to most vehicles.