With more than 3 million visitors entering its gates every year, Antoni Gaudí's Sagrada Família is the most visited tourist attraction in Barcelona. Unfortunately, the admission fees and queues to get in are at least equally impressive as the yet-unfinished cathedral itself.
Alternative: Torre Agbar
Located between Av. Diagonal and C/Badajoz and looking rather unspectacular during the daytime, this 38-storey tower is a real eye-catcher after dark, thanks to its colourful nocturnal illusion. Designed by French architect Jean Nouvel and somewhat similar to The Gherkin in London, Torre Agbar has become an integral part of the city skyline and should be on every first-time visitor's list of things to see in Barcelona.