In 1527, the forces of the Holy Roman Emperor Charles V sacked the city of Rome and Pope Clement VII was forced to retreat northwest to the small city of Orvieto.

Perched on top of a mountain, Orvieto was defensible and offered a sweeping view of the valley below. Unfortunately, a new threat faced the Pope and his forces that could force them off the mountain even before the invading army could reach them: the water supply in the city could not handle the extra influx of people for very long.

Clement wasn’t about to surrender just yet, so he had the architect Antonio da Sangallo the Younger design a massive well to be built on the edge of the city near a spot overlooking the valley below. Thankfully for Clement, he was able to come to terms with Charles V and return to Rome in 1529 in one piece. He left Orvieto before the well was completed, but what he left behind was a feat of Renaissance engineering.

The 174-foot-deep well is accessed via two winding ramps nested inside each other. The idea behind this was that donkeys carrying water containers could walk down one ramp, then back up the other. A walkway crosses the base of the well connecting the two ramps. Rows of vaulted stone windows on the ramps open up into a central open column, providing light and ventilation.

The name of the well, the Pozzo di San Patrizio (the Well of St. Patrick), was a refence to a doorway to Purgatory that St. Patrick had been shown in Ireland, according to a legend.

Some quick background:

Clement’s predicament was partly of his own making, but not entirely. He had supported the Holy Roman Emperor, Charles V, in his ongoing conflict with the King of France. However, when it looked like the political balance was shifting, Clement signed a deal with the French king. Unfortunately for Clement, Charles was short on funds to pay his troops, and the angry forces of the Holy Roman Empire decided to take matters into their own hands and storm the wealthy and poorly-defended city of Rome as retribution for this slight.

The attack was incredibly swift and brutal. The Swiss Guard bravely stood their ground to give Clement and his bodyguard time to escape to the Castel Sant’Angelo — and were slaughtered. Every member of the Swiss Guard who stayed behind to buy time for Clement VII was killed on the steps of St. Peter’s Basilica. Charles’s rogue army, and the plague caused by the decaying corpses they left in the streets, killed more than half the population in Rome. After holding out in the Castel Sant’Angelo for seven months, Clement managed to flee to Orvieto.

Clement VII was a member of the powerful and notoriously corrupt Medici family (he was born Giulio de’ Medici), but historians seem to agree that he wasn’t particularly corrupt himself. Certainly not as much as other members of his family. But he was plagued by a series of crises, poor decisions and bad luck.

Clement commissioned works by both Michelangelo and Raphael, including Michelangelo’s The Last Judgement fresco in the Sistine Chapel (he was the third Pope after Julius II, the Pope who originally commissioned Michelangelo to begin work on the Sistine Chapel). He was also the Pope who refused Henry VIII his divorce from Catherine of Aragon, thus precipitating the Church of England’s break from Catholicism. Coincidentally, Henry was suing for divorce while Clement was hiding out in Orvieto, and Catherine of Aragon (Henry’s first wife) was the Holy Roman Emperor’s aunt.

The entrance to the well
Orvieto offers spectacular views of the valley below

The view out one of the windows along one of the two ramps leading into the well
Once at the bottom of the well, visitors walk across a walkway to the second ramp
The full scale of this well is hard to capture in a photo. 
The lighting was far from optimal, but this was the walkway at the bottom of the well
One of my favorite pictures of the well. It wasn’t only meant to be practical: it was meant to be art