the Sagrada FamíliaConsistently the top recommendation for visitors, and worth allowing a half day rather than squeezing it between other stops.
Local culture beyond the checklistthe Gothic Quarter and Barceloneta Beach are where Barcelona feels least like a tourist itinerary and most like the actual city.
A well-known second stop: La RamblaRounds out a first visit nicely alongside the bigger-name sights.
Easy onward travelBarcelona's transport connections make it simple to extend the trip into the rest of Spain if you have the time.