Perhaps no architect has ever had such an influence on a major city as comprehensively and spectacularly as Antoni Gaudí (1852-1926). The great Moderniste (or Art Nouveau) master's still unfinished Sagrada Família (Expiatory Temple of the Holy Family) has become Barcelona's most emblematic structure, while numerous other buildings, parks, gateways, and other works in and around the city provide a constant Gaudí presence throughout the Catalonian capital.

Gaudi undertook the task of building his masterpiece in 1883 based on the plan of a Gothic basilica. His aim was to create a "20th Century Cathedral". Josep. M. Subirachs, a Sculptor, joined the project team to work on the sculptures on the Portal of Passion in 1987. Today, the constructed part is open to visitors as well as the small Museu del Temple Expiatori de la Sagrada Família with maquettes and drawings showing the construction process. The towers can be climbed as well offering incredible views of the city.

Work continued on the church based on Gaudí's general plan and studies. Unlike many churches, Sagrada Família survived during the Spanish Civil War, when many churches were burned; it was and is seen as a kind of symbol for the city of Barcelona. Although Sagrada Família is not the Cathedral of Barcelona (which dates from the 13th century), it is sometimes called Barcelona's third cathedral. Sagrada Família is still unfinished today and it is anybody's guess when it will be completed. Sagrada Família is a combination of Modernista elements and a unique version of the Gothic style--seen primarily in its height, use of rose windows and arches, triple portals, and architectural sculpture.