Located in the Trigno Valley, perched on a hill, Trivento has a long history. The legend tells that both sort some centuries before Rome. The first nucleus of Terventum was inhabited by the Samnites, and colonized by the Romans after the Samnite wars in the III century a. C. It was part of the Regio IV under the government of Augusto, and in the Middle Ages, already from the VI century saw the construction of the primary cathedral, which will become the seat of the diocese in 1076. On the top of a hill near the church, was built the ducal castle, who passed in the thirteenth century to the Angevins and then to the Caldora.
The structure of the Castle has high walls, with an irregular plan, and two main entrances. The interior has been modified over the centuries, the underground part is spartan because it was used in the past as a prison of while the piano nobile preserves a hall with frescoes.
The Scalinata di San Nicola has a step for every day of the year (365) that lead to the high part of the country, called Piano. The Cathedral of Saints Nazario and Celso and Vittore boasts a crypt sort on an ancient altar dedicated to the goddess Diana, dating back to some centuries before Christ.