10 Epic Construction Projects That Took Centuries to Complete (5 of 6)

8. Florence Cathedral (Florence, Italy)—140 Years

The Gothic structure of Santa Maria del Fiore was begun in 1296, but when it came time to build the dome, nobody at the time could figure out how. Fortunately, 140 years later, engineer Filippo Brunelleschi developed an innovative technique that made it possible to put up the dome without the need for scaffolding, marking a truly defining moment of the Renaissance. The façade wasn’t finished until 1887, blending old and new in harmonious marble.

9. Cathedral of St. John the Divine (New York City, USA)—130+ Years

Construction began in 1892, and the original architectural style was intended to be Romanesque-Byzantine. However, the design shifted to Gothic Revival by the 1920s. A pair of world wars, the Great Depression, and shifting priorities have kept the cathedral from being completed. In fact, while it is the largest cathedral in the world, it is technically only two-thirds finished, and as a result it has earned the nickname “St. John the Unfinished.” Nonetheless, it functions as a vibrant cultural and spiritual center, hosting concerts, art, and community outreach, with additional work ongoing into the 21st century.