County Limerick is located in the province of Munster, and is also part of the Mid-West Region. It is named after the city of Limerick and borders four other counties: Kerry to the west, Clare to the north, Tipperary to the east and Cork to the south. It is the fifth largest of Munster's six counties in size, and the second largest by population. The River Shannon flows through the city of Limerick into the Atlantic Ocean at the north of the county. Below the city, the waterway is known as the Shannon Estuary. Because the estuary is shallow, the county's most important port is several kilometres west of the city, at Foynes. Limerick City is the county town and is also Ireland's third largest city. It also serves as a regional centre for the greater Mid-West Region. Newcastle West, Killmallock & Abbeyfeale are other important towns in the county.