Ferento is an ancient Roman town a little less than 10 kilometres from Viterbo. At the beginning of the 20th century excavations started and a large part of the city, destroyed in a war with Viterbo, was recovered. Its Roman name was Ferentium.
During the times of the empire the city had its most flourishing period.
After the barbarians invaded Ferento in the middle ages, the city lost a lot of its power.
During a war between Nepi and Ferento, the former called for help from Viterbo. When the Viterbese fighters were on their way to the battlefield, Viterbo itself remained unprotected and was itself attacked and plundered by the Ferentini. A priest stayed behind and warned the troops, who charged the Ferentini on their way back. The Viterbese army emerged victorious from the battlefield.
Although the citizens of Ferento swore to accept their subordination forever, the soldiers of Viterbo invaded the city and looted what they could take and destroyed what was left.
The inhabitants of Ferento fled and spread out over the region. Some of them went to live in the nearby caves. It is in this way that Grotte Santo Stefano was founded.
The district of San Faustino in Viterbo itself was also originally inhabited by these refugees.
After having been virtually forgotten for centuries, at the beginning of the 20th century the first excavations started. At first some some statues were found, then the theater came to light, followed by a section of the road, part of the baths and some houses.
Today, during the summer months, the ancient theater is again used for performances.