During the 16th century, Shibenik was one of the best protected European cities with at least five fortresses protecting it. St. John's Fortress is the highest city fortress, located on top of a hill about 115 meters above the city center. The old town takes about 10 minutes walk uphill. The fortress dates back to 1646., when it was built to protect Shibenik from Turkish attacks. The townspeople were so terrified by these invasions that they helped build the fort, which was completed in a record six weeks. The views from the top are also stunning.