St. Patrick's Well: Within all
Orvieto's attractive also a special mention to the Pozzo di San Patrizio
(Saint Patrick's well), by Antonio da Sangallo, a stately work of
hydraulic engineering built in the period 1527-1537, to assure water
for the city during the wars and states of emergency.
helix staircase will let you walk down into the well (It is 62 meters
deep and almost 13 meters in diameter, 248 steps for each ramp) and come
back up again without retracing your steps.