The Iron Gate of Diocletian’s Palace (Croatian: Željezna vrata, Latin: Porta ferrea) is one of the four entrances into the palace (the western entrance). It was the entrance point for troops entering the palace.
As part of the defensive system, it consisted of an outer and an inner gate separated by a courtyard. In the 6th century, the bell tower of the Church of Our Lady of Zvonik was added to the inner wall of the gate, and the city clock was added to the outer wall after the city expanded west to and around Pjaca.
The Iron Gate is the only gate of the palace that has remained in constant use to this day, and it became especially important after the city expanded outside of the palace.
