Barcelona is a two-hour drive from Mas del Rey. Perhaps quite much for a day trip, but Barcelona has so much to offer that a combination with a few nights in Barcelona would be a serious idea. Barcelona is astonishing: there is too much to mention. The famous Ramblas, the Mercat, the Sagrada Familia, Park Güell and other fairy-tale architecture of Antonio Gaudi.
Or the Barri Gotic, the Miro museum, the Camp Nou stadium, that leaves a deep impression even you are not attending a game of FC Barcelona but just take the guided Stadium Tour. An overwhelming city that is very sophisticated and at the same time, full of history and tradition. Here also goes: a lot of information via the links at the bottom.