Carsulae was probably born with the consular Flaminia road which runs through it from one side to the other. Or it was founded from scratch or sprung up from the agglomeration of the populations pre-existing in the area of whom evidence remains, especially on Mount Sant'Erasmo. What is certain is that during the period of the Roman Empire it was a great city, as can be seen from the richness of epigraphs, the size of public buildings, the forum, the amphitheatre, the theater, the thermal bath, the great arch of St. Damiano which marked the north exit. Most of the remains have still to be brought to light, even if the excavations in Carsulae had already begun in the 17th century.
The cause of the rapid decline of the city is unknown. These hypotheses cannot be discarded: from the instability of the land, because of the sinkhole in the western part of the city, to the bloody destruction by some army or other.
A city surrounded in a shroud of mystery, above all for its sudden end: it reached the peak of its splendour in the lst and 2nd centuries B.C. but already in the 3rd century there were few records which referred to Carsulae, which stopped being mentioned in the 4th century.
The issues behind such a sudden end have given rise to much speculation, also relatively to the role played by this city, which acquired wealth and importance
with Christian penetration in Umbria, but immediately after, fell irredeemably. A transit centre, which acquired large spas, a basilica, a monumental forum; dedicated a vast area to leisure activities, built an amphitheatre with a main axis of nearly ninety metres, and a theatre; and in the forum zone built two twin temples, "I Gemini", a presence which gave vent to fascinating theories, although they appear far-fetched, in which Carsulae was once an important Celtic religious centre, the reason why it was damned to disappearance by the overtaking Christian religion. In the middle ages, the church of San Damiano was built on preexisting Roman structures, what remains of two convents, also destroyed, whose vestiges followed those of Carsulae, becoming a quarry of square-shaped stones reused for new buildings in the surrounding areas and for Palazzo Cesi in Acquasparta.
The “U. Ciotti” Visiting and Documentation Centre is the exhibition inside the area that hosts a selection of finds referring to the daily life culture and of the artistic production: ceramics, glasses, lamps, marble sculptures (the portrait of the emperor Claudio and the statue of Dyonisus), sarcofagi made by lead and by local stones, architectural terracotta.