Ključ Castle

Ključ occupies a compact, elongated position on the far southwestern flank of Babe mountain beneath Rudi brdo (1,167 metres). The fortress is set where limestone boulders constrain the outer defenses and where steep rock protects the eastern rampart of the upper enclosure. A small mosque stands on a prominent knoll called Begova bašča about fifty metres from the old fortifications, marking a close relationship between the settlement and the hilltop stronghold.

The surviving layout encloses an interior courtyard measuring roughly 51 by 19.2 metres. The principal entrance retains door frames that measure about 1.70 metres high and 0.80 metres wide; the ground immediately before the lower threshold was levelled, and a short flight of steps above it led onto the patrol walkway. The upper town is ringed by an outer rampart that reaches approximately seven metres in height and narrows to a maximum thickness near 3.5 metres. Access to the upper ward’s main gateway was made through a side wall opening whose clear dimensions are recorded as about 2.00 by 1.40 metres.

A main tower rises on a square base of about eight by eight metres, its walls almost 1.8 metres thick, and this tower shows a limited number of embrasures intended for hand-held firearms and edged weapons. South of the primary entrance stands a square tower reported with dimensions of seven by forty metres that served as a dungeon. Several curtain walls are between 0.8 and 1.0 metre thick and incorporate a supervised concealed exit leading down toward the lower town. The northeastern ramparts preserve openings for cannon and numerous narrow vertical slits designed for close defence.

On the approach to the dungeon there are remains of a residential structure whose exact function has not been identified. During the period of Herzegovina’s control the walls received reinforcement built as irregular stonework—stones set without regular courses and packed with small fragments—bound in lime mortar, a construction technique characteristic of the medieval phase of repair. The site today survives as a ruin. Following investigations after 1878, two artillery pieces from the site were taken to the National Museum in Sarajevo, and medieval stećak tombstones from the nearby hill Ćućenica were also transferred to that museum, forming part of the material record associated with Ključ.