Rye Island (Hungarian: Csallóköz , Slovak: Žitný ostorv) is a river island in southwestern Slovakia, extending from Bratislava to Komárno. The island lies between 3 rivers, which create the continuous boundary of the island: the Danube on the South, its tributary Little Danube on the North and Váh on the East. The island is a major part of the Danubian Flat. It is the biggest river island in Europe with an area of 1,886 km², being 84 km long and 15 - 30 km wide. The main towns on the island are Komárno, Dunajská Streda, and Šamorín. The island is an important reservoir of drinking water and agricultural region.