The diocesan Museum of Gaeta is located in a historic building, Palazzo De VIO, which belonged to a local native cardinal Tommaso De VIO. Over the past few centuries the Palace was rebuilt several times, which completely changed its original appearance.

The idea of creating the Diocesan Museum was founded in 1903, the year commemorating construction of the new facade of the Cathedral of Gaeta, dedicated to St. Erasmus and the assumption of the virgin. Then was a beginning collection of medieval and later religious subjects. In the following years the collection was added paintings from the Central nave of the Cathedral, which survived until our days, from the 13th century. Collected exhibits the steel core to create an impressive art collection and a small archaeological Museum. Among the exhibits were pictures of religious buildings destroyed during the Second World war, destroyed and secularized churches.

In the 1950s, has made a final decision on the establishment of the Diocesan Museum, which was officially opened on the cloister of the Cathedral in 1956 year. And in 1998, the year the Museum's collection was moved to a specially renovated Palazzo De VIO.

Today in the Diocesan Museum you can see paintings on canvas and wood, from the 13th century and until the second half of the 19th century. All work, most of which are devoted to religious subjects, is the exhibits from the old Museum, the Cathedral and other churches, now closed for worship. On the paintings presented here, you can trace the development of artistic ideas Campaign for several centuries. In General, this collection is the largest in the southern Italian region of Lazio, which today is Gaeta.

A great number of paintings in the Museum owned by a local artist Giovanni Gaeta, who worked in the second half of the 15th century. Among other artists – artists Scipio Polycone, Sebastiano Conca, Riccardo Quartararo, Teodoro d errico, known as the Dutchman, Girolamo Imparato, Fabrizio Santafede, etc.

In the private drawing room of the Palazzo De VIO can see two Byzantine cross, the tabernacle and the goblet of Pope Pius IX in the mid-19th century. Also in the gallery exhibited choirs 1569-70-th years of the work of Vincenzo Ponta.