Manuel's apartment is well located for walking to many Barcelona attractions including MNAC (<10 mins) in one direction and La Rambla (15 mins) in the other, plus Plaça Espanya (10 mins), etc. Easy check in by a friend of Manual's and very good pre-stay communication.
Barcelona tip (not related to Manual's great apartment): watch your phone/wallet/handbag at all times as thieves abound. But don't let this put you off visiting this great city (just be vigilant)