Limerick is the fourth largest city in the Republic of Ireland, and the principal city of County Limerick and Ireland's Mid-West Region. Population wise, it is the fifth largest city in all of Ireland. When taking the extra-municipal suburbs into account, Limerick is the third largest conurbation in the Republic of Ireland, with an urban population of 90,757. Limerick is the second-largest city in the province of Munster, an area which constitutes the midwest and southwest of Ireland. The city is situated on several curves and islands of the River Shannon, which spreads into an estuary shortly after Limerick.