The Cathedral of Sant Erasmus is the main Roman Catholic Cathedral of Gaeta. It was first built in the 7th century and then rebuilt several times – in the 10th, the 17th and 18th centuries. In the 20th century has been replaced by its facade.

The current neoclassical building is the result of the reconstruction carried out in the 18th century by order of Ferdinand IV of Bourbon. The facade of the Cathedral was built in 1903, the year in neo-Gothic style: it is remarkable portico, surmounted by a triple Lancet window in the center. Pediment over a circular window of the socket was made in the mid-20th century from pale limestone tufa.

Inside, the Cathedral consists of a Central nave with side chapels and transepts, chancel space and relief of the apse. In front of the presbytery are the wooden choir of the 16th century, resting on two marble columns. Also preserved columns of the original medieval building. Under the altar is the crypt, which is decorated in 16-17-th centuries colored marble and frescoes. You can reach it from two side aisles by two large staircases. The interior of the Cathedral is decorated with numerous works of art, for example, Easter candles, decorated with carvings of the 13th century.

The Cathedral of Sant Erasmus stands on the spot where in the 7th century, outside the city walls, was built the Church of Santa Maria that gave shelter to fleeing from Formia bishops. In the 10th century, after the discovery of the relics of St. Erasmus, the Church was extended, and accepted the Deposit of the Holy remains. In 1106, the year it was consecrated by Pope Pasquale II.

To the right of the Cathedral stands the 57-meter high bell tower in Arab-Norman style, built in the 12th century by the architect Niccolo d’ Angelo. At the entrance you can see a bas-relief depicting a sea monster swallowing the biblical prophet Jonah. The Foundation of the tower was built from fragments of ancient Roman monuments, in particular, the mausoleum Atrative. An impressive staircase leads you inside, where you'll find Roman sarcophagi from archaeological area of Minturno. The bell tower, like much of the surrounding area, was seriously damaged during the Second World war, but was restored and has remained an important element of the urban landscape.