The St. Patrick’s Well is a historic structure built by Antonio da Sangallo the Younger in Orvieto, between 1527 and 1537, by Pope Clement VII, fresh from the sack of Rome and eager to protect themselves in case of a siege of the city in which he had retired. The work of the well – designed to provide water in the event of disaster or siege – were concluded during the papacy of Paul III (1534-1549).
Access to the well, a masterpiece of engineering, is guaranteed by two-way spiral ramps, fully autonomous and served by two different ports, making it possible to carry with mules water extracted without obstruct and without having to resort to the only road leading to the town from the valley floor.
Well, deep 53.15 meters,  was carried out digging in the tufa plateau crust and the upper Tiber valley where the town of Orvieto, a stone quite hard but that is suffering now, after several centuries, discharges sewage.
It has a cylindrical shape with a circular base with a diameter of 13 m.
The steps are 248, and windows that give light are 70.
Perhaps the aura of the sacred and magical that accompanies the deep cavities, or for pure imitation of film models, modern tourists will throw nickels in the hope of return.
The well was called St. Patrick because he remembered the cave that existed in the place (in Ireland) that now bears the name of St. Patrick’s Purgatory.