The city of Orvieto identifies itself with its cathedral, one of the greatest masterpieces of Italian Gothic, built between 1290 and 1330. Inside it contains a number of works of art of extraordinary value, like the bronze bust of Urban VIII (1568-1644)  by Bernini (1598-16809, the "Madonna and Saints" by Pinturicchio (1454-1513), some frescoes by Gentile da Fabriano (1375-1427), Filippo Lippi (1406-1469), and Signorelli (1445-1523).

The cathedral of Orvieto shows itself as predominantly as a "Gothic cathedral," but there are many styles in it. The first builder for we have some data is the Benedictine Fra’ Bevignate (born in 1250 ca.), who built the three aisles as far as the transept. Under Giovanni Uguccione (14th century), the transept and apse were completed. In 1305, Lorenzo Maitani (1275-1330) strengthened with four arches the sides of transept and the two apses; he designed and modified the façade and continued the construction of the roof. Inside, the artist's hand remains visible in the gallery, located on the wings of eastern buttress, which was completed after his death. On the walls of aisles ten chapels open. The floor of the cathedral is made of red marble; it was started in 1347, and then completed between 1383 and 1388.

The baptismal font was designed and initiated by Luca di Giovanni in 1390 and, in 1406, the Sienese Sano di Matteo (1392 ca.-1434) completed the work. In front of the baptismal font, on the left wall, the "Majesty" stands out, a work by Gentile da Fabriano (1375-1427). The nave is surmounted by a big window of Gothic style, almost 17 meters high and wide about 5, a work begun by Giovanni Bonino of Assisi 14th century), and finished by Nicola Nuti in 1334; the glass is composed of over 40 panels depicting the story of the Virgin and Jesus,  Saints, Doctors and Evangelists. The walls are covered with frescoes of the local school painters, executed by Ugolino del Prete Ilario (14th century) and Pietro Puccio (14th century) between 1370 and 1380. They were restored in 1491 by Giacomo Bologna (15th century) and then by Pinturicchio and Antonio da Viterbo, called the "Pastura" (1450 ca.-1516). The apse is divided from the transept by a staircase with travertine, surmounted by a balustrade of dark red marble, a work by Ippolito scalza, the author of local "Pieta", carved from a single block of marble.

In the central door, divided into six panels, the "Seven Acts of Mercy" are represented. In the cathedral the "Judgement" stands by Luca Signorelli, a masterpiece of Renaissance, located in the “San Brizio” Chapel, located on the right side of the Cathedral. Inside the chapel, in the first span, centred about the theme of "End Times", we can see the "End of the World"; on the left wall the "Preaching of the Antichrist" is represented, and, on the right, “Resurrection of the flesh”. In the second span, “Christ the Judge" is represented, above the altar. From a corner of the wall, which tells “Facts of the Antichrist”, we see two figures dressed in black, who observe the scene carefully, and have been identified by the Art criticism as two portraits of famous painters Beato Angelico (1396 ca.-1455) and Luca Signorelli.

The “Opera del Duomo” Museum offers an artistic scene certainly out of the ordinary. Let's start with the "Madonna and Child, Saint Catherine of Alexandria and St. John the Evangelist", a fresco of the fourteenth century. After the restoration, it is considered by critics as a work dating from the early fourteenth century, for the construction technique of the halos. Within that chronological stage, many artists acted in Orvieto, whose works, probably left by the same workshop, are collected as a work of Master of the “Madonna di San Brizio”. Worth mentioning is also the "St. John the Baptist," a fragmentary fresco depicting St. John covered with a skin of camel, with his right hand in front of the chest with his index finger stretched upwards. The head of John the Baptist is powerfully shaped and long locks of curly hair and beard are described in detailed. Particularly rich is the halo of the saint, with two concentric bands.

According to critics, the author of fresco was probably of non-local origin, perhaps from Todi. Even the "Madonna of the olive" (XV century, narrating the legend of the Virgin to a baby) seems to have been made by a painter of good quality, perhaps from Siena. "The Adoration of the Magi" (XIV century), finally, although fragmentary, shows the skilful hand of an excellent artist. In fact, it is assumed to be a painter of remarkable technical skills, because the characters are described with great finesse and elegance. As regards the artist, the Art criticism, in the past, believed the work by Pietro di Puccio, but the difficulties of attribution were significant and inconclusive.

Another important fresco is the work by Andrea di Giovanni (1477-1548), the "Nativity and Adoration of the Magi", which was probably part of a larger cycle devoted to childhood of Christ. The review confirms the stylistic attribution to Andrea di Giovanni, a local painter, who trained with Ugolino di prete Ilario, in some frescoes of the Cathedral Tribune, where he was active between 1378 and 1380. More valuable is the fresco of "St. Julian" (XV century). The assessment style of the painting probably dates from the fifteenth century, coinciding with the arrival to Orvieto of Gentile da Fabriano. It is probably the work of some artists of the Pietro di Nicola (15th century) School, who suffered the style of Gentile da Fabriano.