Question: Information:  - The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a sovereign country in western Europe. Lying off the north-western coast of the European mainland, it includes the island of Great Britain (the name of which is also loosely applied to the whole country), the north-eastern part of the island of Ireland, and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another sovereign statethe Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, with the North Sea to its east, the English Channel to its south and the Celtic Sea to its south-south-west, giving it the 12th-longest coastline in the world. The Irish Sea lies between Great Britain and Ireland. With an area of , the UK is the 78th-largest sovereign state in the world and the 11th-largest in Europe. It is also the 21st-most populous country, with an estimated 65.1 million inhabitants. Together, this makes it the fourth most densely populated country in the European Union.  - Trenarth Bridge ( Cornish : Pons Tre Nerth , meaning bridge of Nerth 's farm ) is at the head of the centre head of Port Navas Creek and is between Mawnan Smith and Porth Navas .  - Cornwall is a ceremonial county and unitary authority area 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 . The administrative centre, and only city in Cornwall, is Truro, although the town of Falmouth has the largest population for a civil parish and the conurbation of Camborne, Pool and Redruth has the highest total population.  - The Helford River is a ria (flooded river valley) in Cornwall, England, fed by small streams into its many creeks. There are seven creeks on the Helford; from west to east these are Ponsontuel Creek, Mawgan Creek, Polpenwith Creek, Polwheveral Creek, Frenchman's Creek, Port Navas Creek, and Gillan Creek. The best known of these is Frenchman's Creek, made famous by Daphne du Maurier in her novel of the same name. A little further up river is Tremayne Quay, built for a visit by Queen Victoria in the 1840s which she then declined to make, allegedly because it was raining.  - Port Navas Creek (meaning "creek of the house of elm trees"), or Porthnavas Creek, is one of seven creeks off the Helford River in Cornwall, England, United Kingdom. It splits into three heads with the village of Porth Navas on the west one, Trenarth Bridge on the middle and the east one is near Budock Veane.  - Porth Navas is a small village in Cornwall, England, UK. The village was called "Cove" until the 19th century development as a granite port, the village is at the head of a short creek running off the main limb which runs North from the Helford River. It is situated between Mawnan Smith and Constantine. It lies within the civil parish of Constantine.  - Mawnan (meaning "St Maunan") is a civil parish in south Cornwall, England, United Kingdom. It is situated in the former administrative district of Kerrier and is bounded to the south by the Helford River, to the east by the sea, and to the west by Constantine parish. The population was 1,454 in the 2001 census, rising slightly to 1,476 at the 2011 census.  - In England, a civil parish is a territorial designation which is the lowest tier of local government below districts and counties, or their combined form, the unitary authority. It is an administrative parish, in contrast to an ecclesiastical parish.  - Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. The word "granite" comes from the Latin "granum", a grain, in reference to the coarse-grained structure of such a holocrystalline rock. By definition, granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume.  - Mawnan Smith is a village in the civil parish of Mawnan in south Cornwall, England, United Kingdom. It is situated approximately three miles south of Falmouth. The population of the civil parish at the 2011 census was 1,539.    What entity does 'trenarth bridge' has the relation 'located in the administrative territorial entity' with?
Answer:
cornwall