Where is El Rastro in Madrid (the famous flea market)?

Is it close to Puerta del Sol? I mean, walkable distance? Thanks for your help!

It starts just south of Plaza Mayor at Plaza de Cascorro (very near La Latina metro stop) and goes downhill to Ronda de Toledo. It branches off to a few other streets. At the top of the hill is mostly new stuff, then it turns into the real serious junk!

It is very walkable from Sol. It is a pretty steep hill so I like to walk down it and then catch the Metro at Puerta de Toledo to go where I want next.