The military fortification, with its monumental Sea Gate, is a Renaissance-style enclosure of 131,480 m², dating from the year 1543.

The archaeological site inside the fortified enclosure consists of: remains of the Hellenistic district in the Greek settlement of Rhode; a Roman villa dating from the 2nd century BC to the 6th century AD; a Paleo-Christian necropolis; several Visigothic buildings; the 11th-century Lombard Romanesque monastery of Santa Maria and remains of the fortified medieval town; remains of several military buildings dating from the last occupation of the citadel in the 16th century; a Museum providing an insight into the history and cultural heritage of Roses, from prehistory to contemporary times; and an Exhibition Hall.

A guided tour of the citadel is a master class in history concentrated in a single space of 17 hectares. The marked itinerary has good information panels. Family and cultural activities are available.