The Odescalchi Castle is the central building situated in the medieval town of Ilok, housing Museum of the Town of Ilok.The Odescalchi Castle is an impressive building built on the foundations of the castle of King Nikola Ilocki from the 15th century. Nikola's medieval castle with the entire Ilok estate, which at the time occupied the greater part of Srijem, were given by Emperor Leopold to Pope Innocent XI Odescalchi and his family as a reward for their help in liberating Ilok from the Ottoman. The Pope's nephews, aristocrats from Italy, expanded the castle and changed its style. The castle was eventually rebuilt in the Baroque-Classicist style. They developed at the time very modern wine cellars beneath the castle and gave impetus to the growth of viticulture and wine production. After 1945, the Odescalchi left their Ilok estate, and their descendants remain a part of the Italian nobility, living near Rome.