A historic Croatian fortress, Kaštilac in Kaštel Gomilica, was surprisingly constructed not by traditional builders, but by nuns. Located in central Dalmatia, the fortress served as a vital safe haven for families across centuries. The unique origin of its construction challenges conventional expectations of medieval fortress building. Details regarding the specific nuns involved and the motivations behind their undertaking are further explored in a recent report. This unusual architectural feat highlights an unexpected chapter in Croatian history. Kaštilac stands as a testament to the resourcefulness and determination of its builders. The fortress's enduring presence continues to intrigue and inspire.