Roman Catholic Diocese of Sisak

Cathedral of Exaltation of the Holy Cross (Croatian: Katedrala Uzvišenja Svetog Križa) is a cathedral in the Diocese of Sisak. It is located in the center of Sisak on Ban Jelačić Square.

The Sisak concentration camp was a concentration and transit camp located in the town of Sisak, in the Axis puppet state the Independent State of Croatia (NDH), from 1941 to 1945, during World War II. It consisted of two sub-camps, Sisak I and Sisak II. The former was used to intern adults destined for forced labour in the Reich and was established in 1941, while the latter was used to detain unaccompanied Serb—and to a lesser extent, Jewish and Roma—children who had been separated from their parents over the course of the conflict. Sisak I was operated by the Germans, whereas Sisak II was administered by the Ustaše, with some German gendarmes guarding its perimeter. The latter became operational in July–August 1942, receiving a group of children who had previously been detained at Mlaka. Living conditions at the children's camp were poor, leading to a high mortality rate. According to survivors, some children were killed by being given poisoned milk or gruel laced with caustic soda. On other occasions, camp commander Antun Najžer administered children with lethal injections. Thousands of children were saved from the camp as a result of rescue efforts spearheaded by the humanitarian Diana Budisavljević and the local communist underground. Sisak II was dissolved in January 1943. The exact number of children who perished there is unknown, but estimates range from 1,160 to 1,600, largely as a result of starvation, thirst, typhus and neglect. In April 1944, the Germans ceded control of Sisak I to the Ustaše. It was shut down in January 1945 and its remaining inmates were dispatched to Jasenovac. In September 1946, Najžer was convicted for his involvement in the atrocities that took place at the children's camp and sentenced to death by firing squad. Memorials commemorating the camp victims were demolished by Croatian forces in the early 1990s, during the Croatian War of Independence. Camp survivor Gabrijela Kolar's sculpture was spared, but has since fallen into a state of disrepair. In post-independence Croatia, the camp's main building was transformed into a theatre and renamed the Crystal Cube of Cheerfulness.

The Sisak Synagogue (Croatian: Sisačka sinagoga) is a former Jewish congregation and synagogue, located in Sisak, Croatia. Designed by Franjo Klein in the Romanesque Revival style and completed in 1880, the synagogue was devastated and robbed during World War II. The synagogue has served as the Fran Lhotka Music School, a music school, since c. 1968.

Sisak (pronounced [sǐːsak]; also known by other alternative names) is a city in central Croatia, spanning the confluence of the Kupa, Sava and Odra rivers, 57 km (35 mi) southeast of the Croatian capital Zagreb, and is usually considered to be where the Posavina (Sava basin) begins, with an elevation of 99 m. The city's total population in 2021 was 40,185 of which 27,886 live in the urban settlement (naselje). Sisak is the administrative centre of the Sisak-Moslavina County, Croatia's biggest river port and a centre of river shipping industry (Dunavski Lloyd). It lies on the D36 state road and the Zagreb-Sisak-Novska railway. Sisak is a regional economic, cultural and historical center. The largest oil refinery in Croatia is here.

Gradski Stadion (Croatian pronunciation: [grǎtskiː stâdijoːn]) is a multi-use stadium in Sisak, Croatia. It serves as home stadium for football club HNK Segesta. The stadium all seating capacity is 8,000 spectators.

Ledena dvorana Zibel is an ice hall in Sisak, Croatia. It was opened on January 27, 2018, and has 1,960 seats.

The Battle of Sisak was fought on 22 June 1593 between Ottoman Bosnian forces and a combined Christian army from the Habsburg lands, mainly the Kingdom of Croatia and Inner Austria. The battle took place at Sisak, central Croatia, at the confluence of the Sava and Kupa rivers, on the borderland between Christian Europe and the Ottoman Empire. Between 1591 and 1593 the Ottoman military governor of Bosnia, Beglerbeg Telli Hasan Pasha, attempted twice to capture the fortress of Sisak, one of the garrisoned castles that the Habsburgs maintained in Croatia as part of the Military Frontier. In 1592, after the key imperial fortress of Bihać fell to the Turks, only Sisak stood in the way before Croatia's main city Zagreb. Pope Clement VIII called for a Christian league against the Ottomans, and the Sabor recruited in anticipation a force of about 5,000 professional soldiers. On 15 June 1593, Sisak was once again besieged by the Bosnian Pasha and his Gazis. The Sisak garrison was commanded by Blaž Đurak and Matija Fintić, both Croatian priests from the Diocese of Zagreb. A Habsburg relief army under the supreme command of the Styrian general Ruprecht von Eggenberg, was quickly assembled to break the siege. The Croatian troops were led by the Ban of Croatia, Tamás Erdődy, while major forces from the Duchy of Carniola and the Duchy of Carinthia were under the commander of the Croatian Military Frontier Andreas von Auersperg, known as the "Carniolan Achilles". On 22 June, the Austro-Croatian relief army launched a surprise attack on the besieging forces, and at the same time the garrison came out of the fortress to join the attack; the ensuing battle resulted in a crushing defeat for the Bosnian Ottoman army, with Hasan Pasha being killed in action and almost all of his army being wiped out. The battle of Sisak is considered the main catalyst for the start of the Long War which raged between the Habsburgs and the Ottomans from 1593 to 1606.

The Sisak Fortress (Croatian: Tvrđava Sisak or Stari grad Sisak) is an early modern lowland fortification built on the bank of the Kupa River before its mouth into the Sava. It is situated in the suburb of modern-day city of Sisak, Sisak-Moslavina County, central Croatia. It is a triangle-shaped structure, mostly made of brick and supported by stone parts. Each corner of the fortress is reinforced with a round tower covered by conical roof. Towers are connected by the more than 30 metres long thick walls with loopholes. Being on the river bank, the fortress has a natural line of defense from the west-southwest, while the other sides are partially protected by the Sava River in the immediate vicinity, flowing southeast. In its history, the Sisak Fortress was damaged several times and subsequently subjected to renovations. Generally, although it needs a renewal today, it is in good condition. It houses the local town museum.

Odra (pronounced [odra]) is a river in central Croatia. It is 83 km (52 mi) long and its basin covers an area of 604 km2 (233 sq mi). Its source is in the Žumberak mountain, southwest of Zagreb. It flows eastwards, passes south of Velika Gorica, then turns south-east, more or less parallel to the river Sava. It flows into the river Kupa near Odra Sisačka, just northeast of Sisak, also just before the Kupa joins the river Sava. The upper flow of Odra has been significantly altered by humans, by the digging of the 32 km (20 mi) long canal Sava-Odra(-Sava) south of Zagreb, as a measure against flooding (designed taking into account the maximum flows of 1964, 1973 and 1974, and first put to use in 1979). There is no certain etymology for the river's name, it could be Slavic or pre-Slavic, and 20th-century linguists did not have a consensus about it.

Staro Pračno is a village in Croatia.

The Kupa (Croatian pronunciation: [kûpa]) or Kolpa (Slovene pronunciation: [ˈkóːlpa] or [ˈkóːwpa]; from Latin: Colapis in Roman times; Hungarian: Kulpa) river, a right tributary of the Sava, forms a natural border between north-west Croatia and southeast Slovenia. It is 297 kilometres (185 miles) long, with a length of 118 km (73 mi) serving as the border between Croatia and Slovenia and the rest located in Croatia.

Novo Pračno is a village in Croatia. It is connected by the D224 highway.