El Rastro, in the old Madrid, is an antique popular market. It used to be the place to sell every old thing. From clothes to parts of an engine. The people just went there with there used things and put it on the floor to wait for someone who wants to buy it.
That was in the past. Now is quite difficult to find that. You need to go to the little streets around the main one : Ribera de curtidores. This is full of new stores selling every thing you can imagine.
Here you can see the begining of Ribera de Curtidores.
OLympus OMD EM1, 7Artisans 35mm f1.2 ISO 320, f 4, 1/400 seg.