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

10. Basilica of San Petronio (Bologna, Italy)—600+ Years

When work began on the Basilica of San Petronio in 1390, it was intended to rival St. Peter’s Basilica in Rome. It’s been 635 years, and we’re still waiting. The lower portion of the façade remains bare brick, a stark contrast to the ornate interior, which features masterpieces like Giovanni da Modena’s frescoes. Political spats and papal interference stalled progress for centuries, but today it remains one of the largest churches in Europe and is a defining feature of Bologna’s civic identity.