The history of this town is closely tied to the line of lords who owned the castrum, particularly the Orsini, who began building the castle over the structure of the old me­dieval country house, the Anguillara and the Giustiniani, who radically changed the layout of the town at the beginning of the seventeenth century. Following the princi­pality of Innocent X, the castle went to the Odescalchi, who became the lords of Bassano in 1854. The building, which is now in poor condition, will soon be re­stored. On the piano nobile, the hall paint­ed by Francesco Albani in the seventeenth century is notable. It is dedicated to the myth of Phaeton, who is depicted with great pictorial effect in the vault, with scenes of Phaeton’s fall from the chariot, while the scenes on the wall show its dra­matic effects on earth, such as burning forests and Galatea fleeing with her ret­inue, Neptune angrily driving his chariot and the waters that recede to reveal the bodies of the Sirens. The scenes from the Life of Diana were dalle by Domenichino, while Paolo Guidotti Farnese did the alle­gories of Aeterna felicitas. The Stories of Psyche have been attributed to Bernardo Castello, a friend of Tasso and of Giovan Battista Marino. The followers of Antonio Tempesti have been attributed with paint­ing the imaginary landscapes that decorate the hall of the Four Seasons. The schools of Zuccari and of Bertoja were also involved in painting the grotesqueries seen in the log­gia. The presence of works completed prior to the rise of the Giustiniani family is docu­mented in the "Camerino del Paradiso" by a scene showing the palace that was still surrounded by hovels dating to the period of the Anguillara.

In the historic centre, the sixteenth-cen­tury church of Santa Maria Assunta in Cielo was built aver the ruins of an early Romanesque chapel. The interior, with a Latin-cross layout, still has the box where the Giustiniani family prayed, as well as the relic of St. Gratiliano, safeguarded in a sil­ver bust. The feast of St. Gratiliano is celebrated on 12th August to commemorate the date he was martyred at Falerii, near Viterbo. As legend would have it, when the sacred relic was being brought from Civita Castellana to Sutri, the head fell out of the box containing it and rolled away, stopping at the site where the church of Bassano was later built. At the hamlet of San Filippo, located near the town, is Sanctuary of Madonna della Pietà. Each year on the Sunday following the Ascensione, a unique procession of men dressed only in white winds its way to the sanctuary. Along the road to the railway station, the impressive complex of the Monastery of San Vincenzo is worth seeing. It has a vacation house for visitors and pilgrims. The monumental church of San Vincenzo was built by Vincenzo Giustiniani around 1630 as an aristocratic mausoleum. The plans were probably drawn up by Carlo Maderno and Francesco Borromini. It was supposed to be the centre of a village (called Giustiniano) that was never built. In the sacristy there is a marble statue of Salvatore Portacroce, attributed to sculptor Ippolito Buzio. A canvas by the Flemish school depicting St. Vincent, martyr, hangs over altar in the left transept.

The enormous monastery was built immediately after the war by abbot Ilbranda Gregori (Benedictine-Sylvestrine order) to house and teach poor children.