The town's name derives probably from the Umbrian dialect and refers to an "arbutus tree", that can be frequently encountered in the area. Municipality in the province of Terni, located on a hill, completely surrounded by a superb environment, on the border with Lazio and Tuscany, Allerona is a medieval town that still preserves traces of ancient walls and two gates, and also several remains and signs of the presence of the Roman Empire in its territory. In the historical main center features several fascinating corners that can be admired.
Allerona was inhabited since ancient times by the Etruscans, and later was conquered by the Romans, taht founded the settlement. At that time, the Via Cassia was built, a major artery of communication throughout the Empire. During the Middle Ages, the town was an important outpost of the city of Orvieto, and was a stronghold of Monaldeschi and Filippeschi families. In the late XV century, Allerona was looted and badly damaged by the troops of Charles VIII, while in the XVI century, it acquired a certain autonomy and economic, civil and legal order. Later, for a long period, it submitted the domain l of the Papal States.
- the Church of Our Lady of the Water, named so, because of its building near a source, erected in the first half of the XVIII century with an octagonal shape, where once stood a smaller chapel, previously built in the XV century;
- the Church of Santa Maria Assunta, dating from the XII century, features a single nave plan with an apse, decorated in the late XIX century by Viligiardi;
- the Church of San Michele Arcangelo was built around the XII century and restored several times;
- the old Hospital of the Poor, built in 1373;
- the old City Walls;
- the Gate of the Sun, which originally represented the main entrance to the castle;
- Villa Cahen;
- Palazzo Visconti;
- Ponte Giulio.