A short walk from the Plaza Mayor is Madrid's most famous and popular square the Puerta del Sol. This is literally the centre of Madrid - where the radial network of roads converge. The square is semi-circular in shape and has two large fountain in the centre. This is a really busy place and full of people any time of the day. There are lots of popular shops - including an Apple flagship Store, cafes, restaurants and bars around the square. It's a great place for people watching and to soak in the Madrid city life.
Off Puerta del Sol are some of the main shopping and commercial streets in Madrid. All of them have different characters and are great for wandering around.