You now have a free day to explore El Born, the heart of medieval Barcelona. Today its maze of narrow streets is crammed full of specialist food shops, barista coffee hangouts and old-time tapas bars.
In amongst these, several grander buildings stand out. We recommend you visit the spectacular Santa Maria basilica, the ridiculously ornate Palau de la Música (designed by Gaudí's teacher) and the El Born market-turned-cultural centre, which houses substantial remains of the 18th-century village which transformed the area.
El Born blends into Ciutadella Park, the city's green lungs and a place to stroll, people-watch and listen to the parakeets squawk. You'll also pass the Arc de Triomf, created for the 1888 World Fair in which the park took centre stage. There'll be more on this and the park's central role in the story of Barcelona as you go.
To help you on your way, we recommend a brilliant audio tour that you use on your smartphone. The clever part is that it navigates via GPS, so you put your phone in your pocket and just go where your guide tells you. Really easy, and a lot of fun.