text: I rearched now, looked at other maps, historic maps, found in the Google Photo search, sometimes it is just called "Del Gigante". The other streets around are all "callejónes", which means alleyways. In order to close one OSM note, I would aggree to call it "Callejón del Gigante", despite the visible street sign says differently. 
  IMO in this case, Google Street View is a valid source, because street names do not change that often like shops or store fronts.