Pope Clement VII commissioned Antonio da Sangallo the Younger to build a new well to ensure the water supply in Orvieto, Italy. The depth of the well is 63 meters, with two stairs of 248 steps each and 72 windows for ventilation and lighting.
As they are two independent stairs, and not just one, they would allow the pack animals to go down to get water through one of the ramps and return through the other. The final result was a building without rooms, in which the space only serves to be traversed.