The Tamar River is a 70 kilometre estuarine

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 in northern Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

 formed by the merging of the North Esk River

North Esk River

The North Esk River is a river in Tasmania, Australia. It is one of the tributaries of the Tamar River together with the South Esk River. It starts in the Northallerton Valley below Mt Ben Nevis in the states North East joining with the St Patricks River, flowing through Launceston. Launceston's...

 and South Esk River

South Esk River

The South Esk River is the longest river in Tasmania. It starts in the mountains near Fingal flowing through Avoca, Evandale, Longford, Hadspen and finally Launceston. The river is dammed at Trevallyn Dam near Launceston and used for the city's Hydro Electricity scheme...

s at Launceston

Launceston, Tasmania

Launceston is a city in the north of the state of Tasmania, Australia at the junction of the North Esk and South Esk rivers where they become the Tamar River. Launceston is the second largest city in Tasmania after the state capital Hobart...

 (the largest settlement) to its mouth at Low Head

Low Head, Tasmania

Low Head is a small hamlet located on a peninsula by the same name 5 km north-west of George Town, Tasmania, Australia. On the mouth of the Tamar River. It is known for its diving off the Low Head Pilots Station. The town has a lighthouse, a beach and a penguin colony...

, north of the second largest settlement George Town

George Town, Tasmania

George Town is one of the larger towns in north-east Tasmania, on the eastern bank of the mouth of the Tamar River. At the 2006 census, George Town had a population of 4,266. It is the regional centre of the George Town Council Local Government Area....

 and into the Bass Strait

Bass Strait

Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland, specifically the state of Victoria.-Extent:The International Hydrographic Organization defines the limits of the Bass Strait as follows:...

. Low Head Lighthouse

Low Head Lighthouse

Low Head Lighthouse is located in Low Head, Tasmania, about north of George Town on the east side of the mouth of the Tamar River. It was the third lighthouse to be constructed in Australia, and it is also Australia's oldest continuously used pilot station...

 is located at the tip of a peninsula, on the east side of the mouth of the Tamar River.

The Tamar River was named for the River Tamar

River Tamar

The Tamar is a river in South West England, that forms most of the border between Devon and Cornwall . It is one of several British rivers whose ancient name is assumed to be derived from a prehistoric river word apparently meaning "dark flowing" and which it shares with the River Thames.The...

 in Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 which passes Launceston, Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

.