Žabljak lies on a conical hill, near the Moraca River, south of the Upper (Small) Mud (Gornje malo blato) of Skadar Lake . Usually in spring, the lake level rises, and the hill becomes an island connected with the land only by boats. It has not always been like this; it has been recorded that a great part of this flooded area was grown with crops and vineyards up to 1858. A sudden rise in the lake level occurred when the Drim River left its old riverbed and made a new one towards the Bojana River .
Žabljak offered a splendid view of its surroundings.
Žabljak was the old homeland of the Crnojevics. However, it is not possible to establish with certainty how old it is. Whether Žabljak was possibly Lug located at the south side of the Upper Mud and mentioned by Constantine Porphyrogenitus and whether it was the centre of a district (the district of Podlužje, according to the priest of Doclea) cannot be established, although a line from an epic poem «In Žabljak, the town of Podlužje» was recorded as well as the locality of Podlug near Žabljak. Rovinski believes that the chieftains of Serbia built Podgorica, Žabljak and Spuž in the 10th century. According to the priest of Doclea, Žabljak constituted part of the district of Podlužje lying in the lower flow of the Moraca River. Žabljak was first mentioned in the Venetian sources in 1453, when the army of despot Ðuradj was sojourning there. Žabljak flourished during the Crnojevics rule. In 1466, Ivan Crnojevic held his court in Žabljak as a duke under the Venetian supremacy. In the Middle Ages, Žabljak developed into a large settlement consisting of 300 houses, because it represented the crossroads between the Lower and Upper Zeta, as well as the route to the coast. The Turks took Žabljak in 1478, when Ivan burned his court and moved from it. Since then, the Turks were holding Žabljak, as a protruding and strategic point towards Montenegro, for the full four centuries.
The town walls extending from A to B, including a tower (1) near the entrance (2) as well as the one near B, are older than the remaining walls. Similarly, an older part is clearly discerned in the entrance, next to which a rampart with escarpment was subsequently built, along the whole length from B to C. The older parts of the rampart and a semi-circular tower (1) were built of rough-hewn stone, in limestone mortar, in a rather regular manner. These parts contain neither escarps nor cornices. The tower has partly preserved machicolations, which is a rarity. On the remains of an older wall near C, instead of a corner tower, only one pointed protruding part used to stand. The newer parts from A to C, as well as the part from B to C, being built along an older wall, have characteristics of the Venetian building technique, which can be explained by the fact that from 1466 to 1478 Ivan Crnojevic was in the Venetian service and received a pay from them. The upper part of these walls, which is shorter, is vertical, while their lower segments have escarpments. Between the vertical and oblique areas of the facade, a semi-circular cornice was built in. The edifice was built of big blocks of stones set in regular rows.
The Church of St. George, later turned into a mosque, was built in the town in the time of Ivan Crnojevic.
In time of danger, the town was supplied by water from a cistern. A fresh water spring can be found below the town, to the northeast. Other springs had dried out or considerably decreased after the construction of a railroad embankment for the Beograd- Bar railway line, and particularly after the catastrophic earthquake of 1979.