Some of the best tapas bars of Madrid are in Retiro. If you are keen on good wine & tapas, do remember this Metro stop: Ibiza. In this area are concentrated some of the best tapas bars of Madrid, leaded by The Five Great: Laredo, Arzábal (two locations), La Montería, La Castela and Casa Rafa. Also, due to unknown reasons by me, this area gathers several interesting Asturian restaurants. Here is a map to crawl bars, but preferably not on Sunday or Monday when several venues are closed.