Gradac fort is located seven kilometers east from Krepoljin up on a hill which dominates the Mlava plain; it is located at the starting point of Gornjačko – Ribarska gorge. Exactly on that spot the Mlava River makes a great bend, running along craggy cliffs of Djula.
Favorable position for the road control which lead through the Mlava plain towards the mining areas of the Eastern Serbia defined the strategic importance of this fort, and the terrain configuration impacted on its irregular shape adjusted to the cliff which were protecting it from three sides. The most accessible approach was in the south – west.
Due to dense foliage and inaccessibility the ramparts and adjacent facilities are hardly visible and there was probably a hill – settlement too. Stone fort ramparts are about 1m thick. Archaeological findings from comprised only the church with modest dimensions of 9,85х4,75m which was preserved to 1m in the height and located in the eastern fort rim. It was largely burgled and destroyed by treasure – hunters. It had a single – nave base with a semicircular apse in the east and a narthex in the west. There are preserved traces of fresco – painting n the walls and in the narthex there are two brick tombs where most probably rested the church donors. Its foundation was the rock itself, but with visible traces of an older object.
Additional research of the entire complex is necessary to state the exact date of the entire fort and the church itself. According to the existing modest data it is assumed that it was used with intermissions from the early Byzantine to late medieval period.