Barcelona fits a lot into four days because its highlights split cleanly between architecture, old-town wandering, and a nearby mountain — with the beach as an easy add-on.
Day 1: Sagrada Família and the Eixample
Start at the Sagrada Família, Gaudí’s unfinished basilica and still Barcelona’s defining landmark — book your entry time in advance. Afterward, walk the Eixample district to see Casa Batlló and La Pedrera, two more Gaudí buildings, from the outside at minimum.
Day 2: Gothic Quarter and the beach
Spend the morning in the Gothic Quarter (Barri Gòtic) — the Barcelona Cathedral, Plaça Reial, and the narrow medieval streets — then walk through the Born district for lunch. In the afternoon, head to Barceloneta beach for a few hours by the water, Barcelona’s easiest built-in downtime.
Day 3: Park Güell and Montjuïc
Book a timed entry for Park Güell, Gaudí’s mosaic-covered park with sweeping city views — go early to avoid both crowds and heat. In the afternoon, head to Montjuïc hill for the Magic Fountain (evening shows on weekends) and, if you have time, the Joan Miró Foundation or the views from Montjuïc Castle.
Day 4: Montserrat (day trip)
Take the train and cable car (or rack railway) up to Montserrat, the jagged mountain monastery about an hour outside the city. The basilica, the Black Madonna statue, and the hiking trails along the ridge make for a full but easy day trip before flying out.
Practical tips
The Barcelona Card or a bundled Gaudí ticket can save money if you’re doing Sagrada Família, Park Güell, and Casa Batlló or La Pedrera. Watch your belongings closely on Las Ramblas and the metro — it’s the city’s one recurring visitor complaint.