Picnic supplies at La Boqueria
About halfway down La Rambla, you'll find La Boqueria market, with tons of vendors selling meats, cheeses, fruit, pastries and much more. Head down there for a breakfast pastry and get some meat and cheese for a lunchtime picnic. Bring your supplies out to either Parc Guell, the Gaudi-designed park just off the metro, or take the funicular up to Tibidabo and enjoy the view looking down at Barcelona. Either makes for a memorable day outdoors.