The Church of St. Nicholas was built in form of a fortress. It has a trefoil plan with four branches arranged around a central circular core, three of which form the apse, and the fourth the input branch. Its dome-shaped vault is reinforced with circular-ribbed arches above which 8 small towers with battlement as a lookout were built in the 16th or 17th century during Hundred Years' Croatian–Ottoman War. Flanges that are resting on pilasters that are abutting onto the pylons between the apses are placed under the dome. Input branch is rectangular and roofed with a mezzanine leaning on squinch, while three other branches of semicircular conch are translated with semi calotte. The church was built of small stones and has a smooth outer surface. It has very small dimensions; "length": 5.90m, "width": 5.70m, "height"= 6m.