Audio guides and self-guided routes
Self-guiding is a serious touring format: geolocated route apps, neighborhood podcasts and the old-school paper map — the city allows it, and it's cheap.
Apps and audio guides
Route apps cover Gothic, modernisme and Gaudí with geolocation and professional audio; museums lend headsets at the desk. Download before leaving the hotel: battery is the real limit.
Podcasts and maps
Travel podcasts devote episodes to each neighborhood and era: walking El Born with headphones is a free author's tour. The tourist office's paper center map remains unbeatable for improvising.
The sweet spot
One guided tour the first day to get oriented, self-guided the rest: the ratio that works. The city is compact and safe — getting lost is part of the method.