Castello Eurialo is located 7 km Northwest of Syracuse in the Belvedere area. The road leading to the castle gives you the opportunity to imagine the scale of fortifications erected in the city during the reign of Dionysius the Elder. In addition to the fortifications on the island of Ortygia this talented strategist decided to build a wall around the entire settlement, including areas of the Pacific and Naples, which were located at some distance from the centre of Syracuse and could be easily prone to attack.

Between 402 and 397 BC Dionysius the Elder ordered to build an impressive 27-kilometer wall, named after him, along the perimeter of the high plateau Epipoli. The fortifications consisted of two parallel walls, built of rectangular limestone blocks, and reached 10 meters in height and 3 meters in width. Around the perimeter of the walls at equal distance from each other were made secret doors that allowed human thread to pass back and forth without creating congestion, and provide an opportunity for observation in case of any suspicion of assault.

On the highest point of the plateau (120 meters above sea level) towered castle of Castello Eurialo, which had an important strategic location. Its name comes from the name of the promontory on which it stands and which reminds of the nail head ("euryalus" in Greek). This castle is one of the most impressive fortifications built by the Greeks and extant from antiquity. The center of the fortress is surrounded by three consecutive ditches connected by a maze of underground tunnels that allowed the garrison to act independently. So, for example, using underground tunnels can be quickly removed from the ditch set on fire any object thrown by an enemy, before he can cause any damage to the entire structure. And if the enemy still got here, he was immediately disoriented.

Today the entrance to the castle is on the site of the first trench with a length of 6 meters and a depth of 4 meters. A little further lies the second deep trench with a length of about 50 meters, framed by vertical walls, and at once the third length of 17 meters and a depth of 9 meters. All together is a real Chinese puzzle. Three high square pillar to the third of the ditch suggest that once there was a drawbridge providing access to the interior of the castle. The Eastern side is literally dotted with communicating passages, one of which is about 200 meters long leads to gear the castle gate and the exit from it. And the Western side is provided with various underground areas, which kept the weapons and uniforms. For the moat stands a square tower, in which you can see the three square tanks. From the far corner of the tower had a great view down to Syracuse and plain.

After the conquest of Sicily by the Romans in 212 BC, the Castello Eurialo was used for various purposes, and in the Byzantine period, was partially rebuilt.