Iconic building of Enna, stands on the highest point of the city and is one of the largest Medieval castles in Italy. It owes its name to a garrison of Lombard soldiers posted in defense of the fortress during Norman rule. The fortress enabled the city, who was born around it, to take a leading role. Following the decline of Roman Empire, Arabs revitalized the Castle. Roger II of Sicily in 1130 worked the first restoration; a century later, architect Riccardo da Lentini raised 20 beautiful towers to strengthen the embankments around residential halls where Frederick II used to stay during the summer. In those years Castle experienced the culmination of its strategic importance. The development of artillery brought the building to a decline. In 2002, an important excavation has unearthed archeological evidence. For nearly half a century, Castle was home to Civic Opera House. Pisa Tower is the highest and best preserved among six Swabian towers survived, stands on Piazzale St. Nicola and is accessed by a modern entrance. Inside, a stone staircase leads to the first level at which open windows. Majestic silhouette of Citadel has a lighting art that makes it visible from kilometers away.