Knjaževac (, ) is a town and municipality located in the Zaječar District of the eastern Serbia. As of 2011, the municipality has a population of 31,491 inhabitants, while the town has 18,404 inhabitants. The town is situated between three mountains, in the geographical region of the Timok Valley bordering Bulgaria. History In the Roman period, Timacum Minus existed within the present municipality. In 1833, the town, formerly known as Gurgusovac, was liberated from the Ottoman Empire and was administrated into the Krajina nahija of the Principality of Serbia in 1834. In 1859 the official name was changed to Knjaževac. From 1929 to 1944, Knjaževac was part of the Morava Banovina of the Kingdom of Yugoslavia. In 1944, a train tunnel was built in the town, which is depicted in the town's coat of arms. Gurgusovac Tower During the Ottoman period, the fortress, known as the Gurgusovac Tower, after the then name of the town, was built with a purpose to control the Niš-Vidin road. Strategically located, encompassed by the rampart and a deep trench, the fort hosted the company of 100 soldiers. The tower with two floors and a basement was square shaped and the rampart surrounding it was long, wide and tall. After the liberation from the Ottomans, the fort lost its strategic importance and was turned into a dungeon-type prison. Numerous adversaries of Prince Alexander Karađorđević and the Defenders of the Constitution regime were jailed in the tower. Due to its notoriety because of the torture and abuse, it became a symbol of suffering and was nicknamed the "Serbian Bastille". After Prince Miloš Obrenović returned to Serbia in 1858 and replaced Alexander Karađorđević, he visited Gurgusovac and ordered for the tower to be burned to the ground. The tower was razed, with only one wall and an entry gate remaining, while in order to commemorate the prince's decision, the name of the town of Gurgusovac was changed to Knјаževac ("Prince's town") on 17 January 1859. In the 2010s, the area of the former tower was adapted into the open-air cultural venue, including the summer stage. The wall and the gate were kept while the additional walls were rebuilt on the remaining foundations. Geography The municipality extends over an area of 1202 km2 and is the sixth largest in the Republic of Serbia. Its countryside is mostly hilly and mountainous. The highest point in the territory of the