Saint Peter's Basilica
At the heart of the Catholic Church and one of its greatest and biggest cathedrals, the Basilica of St. Peter was built on the burial site of Saint Peter the Apostle between 1506 and 1667. The new structure replaced an older church erected in the fourth century, and it became one of the most expensive and elaborate building projects of the time. Made of marble and stone, it was originally commissioned by Pope Julius II and undertaken by Donato Bramante. During construction, the work fell to Bramante, Raphael, Baldassare Peruzzi and Antonio da Sangallo in turn.
The plans changed a number of times in the process, too, a common factor extending the time line and upping the price of building projects old and new. The original vision for a Greek-cross layout was modified to a Latin-cross layout and back again, and again. Later in the lengthy construction process, Michelangelo, at the advanced age of 72, was appointed chief architect, but didn't live to see the project finished. The final, distinctive piazza design was completed around 1667.
Let's move on to Mont Saint-Michel.