The castle contains remains of the buildings left by its various inhabitants: Romans, Visigoths, Arabs and Christians.

Sagunto Castle covers an area of almost one kilometre in length. It has been a witness to the passage of time and to the presence of the different civilisations who inhabited it: Romans, Visigoths, Arabs and Christians. It was declared a National Monument in 1931 in view of its historical importance. The fortress is divided into seven squares, including the most important, known as the Plaza de Armas or Santa María Magdalena, which is the oldest part of the castle. It contains the remains of the Roman forum, shafts, columns and a cistern carved out of the rock. Remains of the Arab occupation can still be seen in the Plaza de la Conejera square, where an ancient water tank with nine pillars stands in the northern corner.