From Birnje, on the western part of Kozjak, at 631 m of  altitude, a beautiful view over Kaštela Bay and the whole middle-Dalmatian archipelago can be seen. Around the peak the remains of the circular city walls of the castles and fragments of prehistoric ceramics are of particular note. The small medieval church of St. John is situated here. Later the parish church with five marble altars too was dedicated to St. John. It protects relics, the body of St. Felician and a miraculous icon of Our Lady of Mercy dating back to the 16th century.