Brod Fortress The Fortress of Brod The cultural heritage of highest importance ( 0 - category ) . History . The city of Slavonski Brod , Croatia , which was an important strategic and traffic center controlling the border crossing towards Turkey and connecting main commercial trails at the time , in the period between 1715 - 1780 Austria built the large imperial and royal border Fortress of Brod on the Sava River , which along with the fortified baroque towns of Slavonia , namely Osijek and Stara Gradiška , belongs to the great defense system on the border towards the Turkish Empire , designed by Prince Eugene of Savoy in the first half of the 18th century . It was constructed by peasants of the Military Border under forced labor more specifically 634 a day , who also gave 53 horse - drawn carts daily for the transport of material . The regular star - like form of the fortress was determined by the flat - country . It was built of rammed earth , bricks , wood and partially stone , and designed for the accommodation of 4 . 000 soldiers , mostly infantry and 150 cannons . According to an evaluation of the Brod Fortress resistance , during the classical siege with full capacity channels , it would have taken ten days of preparation for the attacks and 46 days for the enemy to take over the entire Fortress . The Fortress of Brod occupied about 33 ha . The military government did not allow for the construction of solid material houses , because the entire town was within the range of the fortress cannons , and consequently , throughout the entire 18th and most of the 19th century , Brod was the town of small wooden houses , roofed by shingle or board . In case of the potential Turkish attack , the town was to be leveled down , in order to provide the artillery with the open space around the fortress . Although being a military border stronghold , the Fortress almost never had the opportunity to prove and demonstrate its combative power . However , there are many preserved fortifications reminiscent of the bygone times and the everyday military life that took place within . The Fortress of Brod was constructed according the Vauban system . It is basically of a rectangular form , while the system of defense channels provides its star - like layout . It consisted of three defense zones : internal , external and southern , and it was protected by two moat areas , water - fed from the nearby stream . The southern part . The southern part of the Fortress was specially reinforced by the fortification named Hornwerk , because of its horn - like layout ( germ . Horn - horn ) . The principal task of Hornwerk was to obstruct the Turkish crossings over the Sava River by implementation of cannons . However , by the end of the 18th century , within the southern defense zone several constructions were erected , such as the Fortress Commander building which today houses The Ivan Zajc Elementary School of Music , Officers ' Pavilion , which apart from the officers ' apartments and which today houses the City Government Headquarters , the Fortress Chaplain apartment ( today here is The Tourist Information Center of Tourist Board ) , the Commander ' s kitchen , the cart - wright ' s and stables , while the remaining free areas were used for orchards , gardens and parks . The internal part . The internal central part of the Fortress is rectangular in shape and consists of four bastions connected by defensive walls . The bastions - pentagonal rammed earth bulwarks brick walled from the outside were organized for the final resistance against the enemies , and were used to monitor the area in front of the Fortress , defend the external walls and the neighboring bastion . Apart from 46 cm high cannon platforms , up to 4 sentry boxes were placed on each bastion for defense purposes . There are curtain walls - the main walls connecting each two bastions . They were brick - built , with a clay overlayer on the top side for the defense path . In the curtain wall interior there are rooms for accommodation of men and ammunition , as well as the workshops required for the Fortress functioning , with passages across the middle . Nowadays , in the reconstructed forge room in the west curtain wall , visitors of the Fortress can meet the Fortress blacksmith . The central part . Within the central part there is the Cavalier - a massive brick - walled one - storey construction in the form of the horse - shoe . In the Cavalier interior there were up to 108 large rooms of identical dimensions - casemates , used for the army logistic purposes , namely for the accommodation of the soldiers , artillery workshops , cart - wright ' s , locksmith ' s , armorer ' s shop , armory , bakery , storage , hospital , pharmacy . Today , the renovated part of the southwestern tract of the Cavalier , on the gross area of 1 . 800 sq . m , houses the unique Ružić Gallery with the first permanent exhibition of the Croatian modern art of the second half of the 20th century . More than 400 works of art from the collection of the Croatian sculptor and painter , Branko Ružić , born in Brod ( Slavonski Brod , 1919 - Zagreb , 1997 ) , as well as his contemporaries and friends are at display in the Gallery . Until 1947 , there was a baroque Fortress church of St . Ann at the center of the Fortress square , protected by two buildings on the south side - the Slavonian barracks , renovated and today housing the classical program high school of Father Marijan Lasković and the Headquarters barracks . The organized tourist groups , previously announced at the Tourist Board , have the opportunity to attend the " living history " programs at the Fortress square , featuring individuals dressed as hussars of the 12 Slavonian hussar regiment from the second half of 18th century , as well as the other characters from the Fortress past such as the Fortress Commander and the Fortress clerk , the Fortress guards and craftsmen etc . The external defence zone . The external defense zone consisted of ravelins - triangular bastions protecting the main walls and obstructing the enemy access to the Fortress . All ravelins are constructed of rammed earth and brick walled on the outside , while in the upper part there is an overlayer and parapets . Within the west and east ravelin walls there is a redoubt - the pentagonal fortification used as a provisional powder magazine and as a gunsmith ' s . Due to the rapid development of the siege techniques , the Brod Fortress lost its defensive task already by the mid 19th century . From that point onwards , Brod on the Sava River started its intensive development , while the old wooden Brod started to disappear . The devastation of the Brod Fortress continues throughout the 20th century . Some objects were destroyed by the army as useless , while the abandoned and unsustainable buildings cave in and dilapidate . In the period from 1945 up until the Croatian War of Independence in the ' 90s , the Fortress serves as accommodation for the soldiers of the National Army of Yugoslavia . Today the Fortress of Brod , cultural heritage site and the unique and monumental example of the 18th century Slavonian military fortification architecture , belongs to the city of Slavonski Brod , decidedly initiating its revitalization .