Ilok is the easternmost city and municipality in Croatia. It is administratively part of the Vukovar-Srijem county. Ilok lies on a hill overlooking the Danube river, which forms the border with the Vojvodina region of Serbia. The population of the city of Ilok is 8,351 (census 2001). The city is home to a Franciscan monastery and Ilok Castle, which is a popular day trip for domestic tourists.