Limerick Port (Port Code:IELMK) established itself as Ireland's premier commercial port on the western side of the country, by the 18th century with the opening of canal systems throughout Ireland. Historically, waterway transport has been key to Limerick's development. Vikings established the city as a maritime trading port. The city's position on a major Irish river system, the Shannon, enabled transport to the midlands of Ireland and further north and west. This was enabled by ease of access from the facilitated by the opening of canals but most importantly to the River Shannon. Waterway transport on the Shannon was regularly used to transport goods from Limerick to Dublin and vice versa however this mode of transport fell into decline in the 20th century. Originally Limerick port was located near the confluence of the Abbey and Shannon rivers at King's Island. Today the Shannon Foynes Port is located further downstream on the Shannon alongside the Dock Road. This general purpose facility port is operated by the Shannon Foynes Port Company who operate all marine activities in the Shannon estuary.