Viterbo is an ancient city and comune in the Lazio region of central Italy, the capital of the province of Viterbo.

It conquered and absorbed the neighboring town of Ferento (see Ferentium) in its early history. It is approximately 80 kilometres (50 miles) north of GRA (Rome) on the Via Cassia, and it is surrounded by the Monti Cimini and Monti Volsini. The historic center of the city is surrounded by medieval walls, still intact, built during the 11th and 12th centuries. Entrance to the walled center of the city is through ancient gates.

Apart from agriculture, the main resources of Viterbo's area are pottery, marble, and wood. The town is home to the Italian gold reserves, an important Academy of Fine Arts, the University of Tuscia, and the Italian Army's Aviation Command headquarters and training centre. It is located in a wide thermal area, attracting many tourists from the whole of central Italy.

Places of interest include:

• Fontana di Piazza della Rocca (12th-16th-century) in the center of Old Town Viterbo
• Viterbo's historic center is one of the best preserved medieval towns of central Italy. Many of the older buildings (particularly churches) are built on top of ancient ruins, recognizable by their large stones, 50 centimeters to a side. Viterbo is unique in Italy for its concentration of 'profferli', external staircases that were a frequent feature of medieval houses. The San Pellegrino quarter has an abundance of them, reflecting an architectural style that is unique to the town and the nearby region.
• Palazzo dei Papi or Papal Palace: A main attraction of Viterbo, the palace hosted the papacy for about two decades in the 13th century, and served as a country residence or refuge in time of trouble in Rome. The columns of the palace are spolia from a Roman temple.
• Cathedral of S. Lorenzo: The Cathedral was originally erected as episcopal see of the exempt bishopric of Viterbo in Romanesque style by Lombard architects at the site of an ancient Roman temple of Hercules. It was rebuilt from the sixteenth century on, and heavily damaged in 1944 by Allied bombs. The Gothic belfry was built in the first half of the 14th century, and shows influence of Sienese architects. The church houses the sarcophagus of Pope John XXI and a picture Christ Blessing (1472) by Gerolamo da Cremona.
• Palazzo Comunale (town hal; begun 1460), Palazzo del Podestà (magistrate's residence; 1264) and Palazzo della Prefettura (police HQ; rebuilt 1771): three civic buildings around the central square, Piazza del Plebiscito. The Palazzo Comunale houses a series of 17th century and Baroque frescoes by Tarquinio Ligustri, Bartolomeo Cavarozzi and Ludovico Nucci.
• Santa Maria della Salute: a small Gothic church with a highly decorated portal.
• Chiesa del Gesu: Romanesque-style 11th-century church. The sons of Simon de Montfort, Guy and Simon the Younger stabbed Henry of Almain, son of Richard, Earl of Cornwall to death as a revenge for the execution of their father.
• Palazzo Farnese: This 14th-15th-century palace was the childhood home of Alessandro Farnese, the future Pope Paul III, and his beautiful[citation needed] sister, Giulia Farnese.
• Rocca (castle).
• Santa Maria Nuova (11th-century), San Sisto (second half of 9th-century), and San Giovanni in Zoccoli (11th-century): three Romanesque churches.
• Palazzo degli Alessandri: a typical medieval patrician house in central Viterbo.
• Fontana di Piazza della Rocca: public fountain in the center of the Old Town, construction 12th-16th century.
• Fontana Grande: public fountain, construction began in 1206.
• San Francesco: gothic church built over a pre-existing Lombard fortress. It has a single nave with a Latin cross plan. It houses the sepulchre of Pope Adrian V, who died in Viterbo in 1276, considered the first monument by Arnolfo di Cambio.
• Sanctuary of Santa Rosa: church is a sober 19th-century reconstruction, where every year a new Macchina di Santa Rosa, or dedicatory tower is displayed.
• Museo Civico: the (City Museum) houses many archeologic items from the pre-historic to Ancient Roman times, plus a Pinacoteca (picture gallery) with works by Sebastiano del Piombo, Antoniazzo Romano, Salvator Rosa, Antiveduto Grammatica and others.
• Orto Botanico dell'Università della Tuscia: botanical garden operated by the university.