The Romans used to build their houses in a way called "Compluvium/Impluvium" which consisted in building the roofs of a inclined form that acted like a funnel to direct the water of the rain towards a cistern that stored the water and later could Be extracted with a bucket by the residents. This same method was used in St. Patrick's well so that every rain, replenish the well for continuous use.

Another characteristic of the well is the way the entrance and the interior ventilation windows are made, not only designed with a form of elongated semi-circle for greater resistance but also concave shape as the well was cylindrical and This was very difficult to achieve at that time, in the same way that the base of the propeller stairs that were used to go up and down continuously, these had a bow at the bottom so that they did not colapsased on the ones that went by water.

San Patrick's well

TECHNIQUE