The most imposing architectural site in the place, unique in the Adriatic region, is the church of St. Mary of Mercy. The fortress church was widened and fortified in 1575 following the Turkish attack under the guidance of the Turkish duke Uluč-Alija in 1571, who looted and burned Vrboska as well as most of the island. Fort Kaštilac is from the same time period, and it served as a guarding post.
The fortress church was fortified at the expense of local people for their defense against the Turks. It is the most beautiful one in Croatia and among the most beautiful ones in Europe from that time period. The church housed some impressive Renaissance art, which has been temporarily placed in the parish church of St. Lovre.
