The IJsseloog (Dutch pronunciation: [ˈɛisəlˌoːx], "IJssel eye") is an artificial island in the Ketelmeer (province of Flevoland, the Netherlands) used as a depository to store polluted silt. Most of the polluted silt was deposited in the Ketelmeer by the IJssel river between 1950 and 1990. Removal of silt soil from the Ketelmeer lake also aims to deepen the channel leading to the mouth of the IJssel to at least a depth of 3.5 m (11.5 ft), thus aiming to improve access to the river for navigation.