It is located in the center of the square with a staircase around its perimeter, a large bath with plant Greek cross, exterior walls with panels and frames rectangular well finished eight columns in the corners, a huge cylindrical shaft in the center and four pillars Octagonal that emerge from the tub ending in pyramid shape.
The base is made up of four high steps and a built-in collection of drains water. The tank has the parapet externally decorated with mirrors between the rectangular frame edge and those of the base.
Source of Sepale “also regulated on the Statute Municipal 1251. Its ancient name seems to derive by Fons Sepalis from “saepes” (hedge or fence), for protections that protected to prevent the animals inquinassero the water tub.
In 1424 the Fountain “great”, was involved in other restoration work. On this occasion it was rebuilt the great trunk column supporting the two cups higher and were carved “quactro heads of liuni from zictare TUCTA water “and was rebuilt entirely lower basin.
The water from this source came from a monumental Roman aqueduct, existing outside the door Romana.
In the cup quatrefoil find this incision that is particularly important because it returns the name of the person to whom was given the task of restoration. This constructor- was Vallerianus restorer who worked under the pontificate of Pope Orsini Nicholas III (1277-1280).
Small capitals are covered in large leaves to bits or more leaves the perimeter of which is characterized by an indentation round.
The bath is accessed via a staircase of five steps that follows virtually the entire perimeter hugging on each side. E ‘for this reason that the fountain and the steps seem one and inseparable structure subsisting in a manner entirely functional.