Antoni Gaudí
Catalan architect, dead in 1926, whose Sagrada Família — taken over in 1883, his exclusive occupation from 1914 until his death — remains under construction more than 140 years after its cornerstone, with its Nativity facade and crypt inscribed as UNESCO World Heritage in 2005. The building's own institution documents the chronology cited here.
Why this wins its question: Gaudí content online is tourism copy. This object limits itself to the chronology the temple's own building institution publishes — primary tier — and states the UNESCO inscription precisely: the 2005 listing covers the facade and crypt built under Gaudí, not the whole basilica, a distinction most coverage misses.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
Antoni Gaudí took over the Sagrada Família project in 1883, and from 1914 worked exclusively on the temple until his death in 1926.
The basilica's Nativity facade and crypt — the parts built under Gaudí's direction — were inscribed as UNESCO World Heritage in 2005, and the temple was consecrated as a minor basilica in 2010.
More than 140 years after the cornerstone, construction continues on the basilica, making it a still-living work of 19th-century architecture rather than a monument to a finished past.