A bit of a saga; Our first taxi took us to a street that he could not drive on. He pointed down the street and we walked about a block without finding the restaurant. None of the shop owners seemed to know where it was either, so we called another taxi. This young man assured us that we were in the wrong place and took us to an old hotel. "yes" we were told, "There was a restaurant called Luna in the hotel" but it was now closed. Another taxi, another ten Euros and a driver who took us right to the spot. Know where you are going before you leave your hotel.
The restaurant is two levels, one a lively bar and then upstairs a rustic restaurant with brick walls and old wooden tables. The building is a medieval stable and it has so much atmosphere. The service was excellent and very friendly. We had a wide variety of tapas and copious amounts of wine. Since I was the only man in a group of seven, I left the table at one point for a "quiet" drink in the bar. The bartender said "Your friends are certainly having a good time; how did you end up with six women?" That story took a half an hour.
IN other words, it is a warm, friendly spot; great food, great people and a real feeling of being in an old and historic part of Barcelona. I recommend it highly, but not for a quiet, romantic dinner. I would call this restaurant "old fashioned high energy."
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.