Rentatack.com
Cocktail bar
I saw your experience and it reminded me! Over 15 years ago (at least, I'm 32 and I was maximum 14 at the time) I was there, or at least somewhere with the same characteristics and the same name, where I tried my first cocktail! It must be the same place, I have to find out! I think it was on Cuenca Street, or at least in that area! :)