A three-day Barcelona trip works best when each day has a geographic focus.
Day 1: Eixample and Sagrada Familia
Use the first day for major Modernista architecture and nearby streets.
Day 2: Gothic Quarter and waterfront
Combine the historic center with a walk toward the coast.
Day 3: Park Güell and Gràcia
Use the final day for elevated city views and slower neighborhood time.
Keep one flexible block
Timed entries, weather and beach plans can shift, so leave some room in the schedule.