The coastal town of Fréjus was founded by Julius Caesar in around 49 BC, and today it is still an important religious and commercial centre of Provence. The cathedral is part of a fortified medieval complex, dating from between the 5th and 14th-century.
The baptistery is the oldest part of the cathedral, dating to the 5th-century, making it the oldest Christian structure in Provence and one of the oldest in France. Built in the ancient Merovingian style with Roman columns, it is similar to the Lateran Baptistery in Rome.
The cloister was added between the 11th and 14th-century and it is made up of a series of pointed arches, resting on double Corinthian columns. Its uniqueness comes from its ceiling, which is adorned with medieval paintings depicting religious scenes and fantastical creatures.