On this day, the 25th March 1436, the Cattedrale di Santa Maria del Fiore (Cathedral of Saint Mary of the Flower) finally completed its construction after 140 years.
It remains to this day the largest brick dome ever constructed, and is one of the most impressive feats of engineering from the Renaissance.
The length of time of construction may have been a tad on the long side, mostly due to the initial architect Arnolfo di Cambio died mid-construction, after which his successor Giotto de Bondone also died mid-construction 35 years later.
During this time there were also several obstructions, such as many changes in patrons, an architect design competition for the dome, and last but not least the Black Death.
If you ever find yourself in Florence, the basilica is a must-visit.