In the Municipality of Campello sul Clitunno, along the banks of the homonymous river, there is an extraordinarily beautiful corner, in an area rich in cultural and artistic references. The waters of the river were celebrated over the centuries by great poets and writers as Virgil (in the Georgians), Plinius the Young, Carducci and Byron, who described its purity as well as the beauty of the surrounding nature. On the edges of the lake there were sacellums, villas and sumptuous spa, where religious feasts were organised every year with contests, theatrical performances and fights between gladiators. By following the watercourse, not far away from the springs, there is the Small Temple of Clitumnus, dating back to a period between the 4th and the 7th century AD.

According to historians, it was initially erected as a Pagan place, although subsequently completed as a Christian Church. The building was erected on one of the several springs of the river, using mainly salvage materials. The structure is made up of overlapping environments: the first one, that belonged to the old pagan building, is located at the ground level and acts as a crypt whereas in the past it was used as the tanks of a pool facing the temple; the second area, on the contrary, belongs to the early Middle Ages period, and was accessible in ancient times only from two flights of stairs ending up in a small portico. The façade is made up of regular rows of calcareous ashlars and is preceded by a portico with four columns, two of which are leant against the furrowed pillars and two are central ones with a palm-leave decoration, ending with elegant Corinthian capitals supporting the trabeation. Some inscriptions were located at the base of the gable, fragments of which are left to us, whereas inside of it there is a wonderful tympanum engraved with bas-reliefs with volute of vine leaves. A small aedicule opens in the wall of the apse containing paintings depicting Christ Pantocrator between the apostles Peter and Paul with some angels considered as the most ancient pictorial examples in Umbria.

The temple had several owners, among which friar Paul who after an earthquake removed a cornice and demolished two side porticos that led to the pronaos through the stairs, and sold them. In 1765 Cardinal Carlo Rezzonico issued a decree for the conservation of this place and between 1858 and 1894 it was accurately restored. In ancient times, the small temple was the object of studies for the architect Francesco of Giorgio Martini and Palladio, who used it as an example for his studies on classic architectures.

During the Middle Ages, the Municipality of Spoleto built a wheat and oil mill near the temple, working with the driving force of the water coming from the river. Today, after its restoration, it has become a Residence, inside of which it is possible to see the ancient mills of the 15th century that are in working order still nowadays. The structure above might be considered as a resource also for a possible collaboration between the public and the private sectors.