Kaštilac was a fortress of a Benedictine Monastery. Kaštilac is the only castle of seven castles in Kaštela. King Zvonimir of Croatia of the Svetoslavić branch of the House of Trpimirović, had donated to a Benedictine from Split possession in the Kaštela field (Kaštelansko polje) in 1078. In the 12th century Benedictine built a church of St. Cosmas and Damian in the Romanesque Architecture style.
Due to the Turkish threat, Benedictine nuns completed the construction of a fortified settlement Kaštilac on the islet of Gomilica in 1545. Entrance to the castle is protected by high tower over the stone bridge with arches. Kaštilac is 40 metres away from the shore, connected with the stone bridge, which was made only of stone. Fortress has square floor plan and in the past, at the entrance was located drawbridge. After the fortress was completed, within the fortification walls arrived inhabitants of the Upper and Lower Kozica, after the Turks had devastated their former villages. In the 17th century the tower lost its defensive function.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.