The Sagrada Familia church began construction in 1882 and is anticipated to be completed in 2026. The UNESCO World Heritage Site recently released a video depicting the final stages of construction of what was Antoni Gaudi's last project and "the most extraordinary personal interpretation of Gothic architecture since the Middle Ages." (via)
The Basilica and Expiatory Church of the Holy Family is a large Roman Catholic church in Barcelona, Spain, designed by Catalan architect Antoni Gaudí (1852–1926). Although incomplete, the church is a UNESCO World Heritage Site, and in November 2010 Pope Benedict XVI consecrated and proclaimed it a minor basilica, as distinct from a cathedral which must be the seat of a bishop.
Though construction of Sagrada Família had commenced in 1882, Gaudí became involved in 1883, taking over the project and transforming it with his architectural and engineering style, combining Gothic and curvilinear Art Nouveau forms. Gaudí devoted his last years to the project, and at the time of his death at age 73 in 1926 less than a quarter of the project was complete. Sagrada Família's construction progressed slowly, as it relied on private donations and was interrupted by the Spanish Civil War, only to resume intermittent progress in the 1950s. Construction passed the midpoint in 2010 with some of the project's greatest challenges remaining and an anticipated completion date of 2026, the centenary of Gaudí's death.