The town of Šibenik has a fortification system consisting of four fortresses: • St. Nicholas Fortress ('''') • St. Michael's Fortress ('''') • St. John's Fortress ('''') • Barone Fortress (
) Only St. Nicholas Fortress is at sea, at the entrance to the Šibenik port, and the remaining three are on land. St. Nicholas Fortress was built on the left side at the entrance to St. Anthony Channel, on the island called
Ljuljevac. The island is situated at the entrance to the Šibenik channel across the
Jadrija beach lighthouse. St. Nicholas Fortress got its name from the
Benedictine Monastery of
St. Nicholas, which was originally on the island, but due to the construction of the fortress, it had to be demolished. At the request of domestic
Croat population of Šibenik, the
Venetian captain Alvise Canal decided to build a fort on the island of Ljuljevac on 30 April 1525. The fortress was designed and built by the famous Venetian
architect and builder Giangirolamo Sanmicheli (nephew of
Michele Sanmicheli). It was built by in the 16th century to prevent
Turkish boats from reaching the port. St. Nicholas Fortress was armed with 32
cannons. ==Architecture==