The Outer Stambol Gate is located in the direction of the main entrance to the fortress. A wooden bridge was originally placed in front of it, which was replaced by an earthen embankment at the end of the 19th century. The gate is characterised by a very simple construction and its original shape has been preserved, it is only missing the wooden doors. It was built of hewn stone with a segmental arch that has clear features of Turkish architecture, and the only decoration on the facade are three small plastic rosettes. Inside the gate, there are rooms for guards, separated by arches.

After passing through this gate, one comes across a hidden path with a wall on which loopholes are sporadically arranged. The first line of defence of the fortress was located there. Behind the hidden path stretches the main fortress moat, 20-25 metres wide and about 5 metres deep. Today the moat is home to tennis courts and basketball courts belonging to the sports clubs Partizan and Crvena Zvezda.