Syrmia County

Vukovar (; , , ) is a city in Croatia, in the eastern regions of Syrmia and Slavonia. It contains Croatia's largest river port, located at the confluence of the Vuka and the Danube. Vukovar is the seat of Vukovar-Syrmia County and the second-largest city in the county after Vinkovci. The city's registered population was 22,616 in the 2021 census, with a total of 23,536 in the municipality.

city in Vojvodina, Serbia

thumb|Ilok Castle Ilok () is the easternmost town in Croatia forming a geographic salient surrounded by Vojvodina. Located in the Syrmia region, it lies on the Fruška Gora hill overlooking the Danube river, which forms the border with the Bačka region of Serbia. The town is home to a Franciscan monastery and Ilok Castle, which is a popular day trip for domestic and cross-border tourists.

Županja (, , ) is a town in eastern Slavonia, Croatia, located 254 km east of Zagreb. It is administratively part of the Vukovar-Syrmia County. It is inhabited by 12,090 people (2011).

Zemun (, ; ) is a municipality in the city of Belgrade, Serbia. Zemun was a separate town that was absorbed into Belgrade in 1934. It lies on the right bank of the Danube river, upstream from downtown Belgrade, north of the Sava. The development of New Belgrade in the late 20th century expanded the continuous urban area of Belgrade and merged it with Zemun.

historic administrative subdivision of the Kingdom of Croatia-Slavonia