The Shannon Callows (Irish: Caladh na Sionainne) are areas of flat land along the shores of the River Shannon. These areas lie between Athlone in County Westmeath, where the river flows out of Lough Ree, and Portumna in County Galway, where it enters Lough Derg, in central Ireland. The shallow grade of the river here results in occasional flooding of the Callows.