Information:  - A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague.  - North East England is one of the nine regions of England that are classified at the first level of NUTS for statistical purposes. It covers Northumberland, County Durham, Tyne and Wear, and the Tees Valley. The region is home to three large conurbations: Teesside, Wearside, and Tyneside, the latter of which is the largest of the three and the eighth most populous conurbation in the United Kingdom. There are only three cities in the region; Newcastle upon Tyne is the largest city in the region with a population of just under 280,000, followed by Sunderland, both of which are located in the metropolitan county of Tyne and Wear. The city of Durham is the county town of County Durham. Other large settlements in the region include Darlington; Gateshead; Hartlepool; Middlesbrough; South Shields; Stockton-on-Tees; Alnwick and Washington.  - Parsons Marine Steam Turbine Company was a British engineering company based in Wallsend , North England , on the River Tyne .  - Northumberland is a county in North East England. The northernmost county of England, it borders Cumbria to the west, County Durham and Tyne and Wear to the south and Scotland to the north. To the east is the North Sea coastline with a long distance path. The county town is Alnwick although the county council is in Morpeth (for the moment, as there are plans to move it to nearby Ashington). The northernmost point of Northumberland and England is at Marshall Meadows Bay.  - Tyne and Wear is a metropolitan county in the North East region of England around the mouths of the rivers Tyne and Wear. It came into existence in 1974 after the passage of the Local Government Act 1972. It consists of the five metropolitan boroughs of South Tyneside, North Tyneside, City of Newcastle upon Tyne, Gateshead and City of Sunderland. It is bounded on the east by the North Sea, and has borders with Northumberland to the north and County Durham to the south.  - Newcastle City Centre, is the city centre of Newcastle upon Tyne, England. Newcastle city centre is the historical heart of the city and the main cultural and commercial centre of North East England. Along with nearby Gateshead town centre, which lies on the opposite side of the River Tyne, the city centre forms the central core of the Tyneside conurbation.   - Tyneside is a conurbation in North East England which includes a number of settlements on the banks of the River Tyne. As defined by the Office for National Statistics, the conurbation comprises Newcastle upon Tynea city forming the urban coreas well as a number of other towns including Gateshead, Tynemouth, Wallsend, South Shields, and Jarrow. The population of the conurbation was 774,891 according to the 2011 census.  - Hexham is a market town and civil parish in Northumberland, England, south of the River Tyne, and was the administrative centre for the Tynedale district from 1974 to 2009. In 2011, it had a population of 11,829.  - Wallsend, historically "Wallsend on Tyne", is a large town in North Tyneside, Tyne and Wear, North East of England. Historically part of Northumberland, Wallsend derives its name as the location of the end of Hadrian's Wall. It has a population of 42,842 and lies east of Newcastle City Centre. The population of the Wallsend ward of the North Tyneside Borough was at the 2011 census 10,304.  - The River Tyne is a river in North East England and its length (excluding tributaries) is . It is formed by the confluence of two rivers: the North Tyne and the South Tyne. These two rivers converge at Warden Rock near Hexham in Northumberland at a place dubbed 'The Meeting of the Waters'.  - The Metropolitan Borough of North Tyneside is a metropolitan borough of Tyne and Wear, in North East England, and is part of the Tyneside conurbation. The borough council's main office is at Cobalt Business Park in Wallsend.    What entity does 'parsons marine steam turbine company' has the relation 'headquarters location' with?
The answer to this question is:
newcastle upon tyne