Question: What is the capital of the state where Oparara Basin is located?

full_context: Document 1: Rukwa Rift Basin: The Rukwa Rift Basin, located in southwestern Tanzania, is an endorheic rift basin that contains Lake Rukwa. It forms part of the East African Rift system and has produced a number of Cretaceous and Oligocene fossils.
Document 2: Gwembe: Gwembe is a small town in Southern Province of Zambia with a population of about 2000 people. It is the largest town in Gwembe District which on Lake Kariba between Siavonga and Sinazongwe Districts. It used to be the District Headquarters until it moved to Munyumbwe some 30 km east of the town.
Document 3: Wa Municipal District: The Wa Municipal District is one of the nine districts in the Upper West Region of north Ghana. The capital is Wa, which also serves as the capital of Upper West Region. Entertainment facilities in the Municipality include Queens Valley and Wizzy Wills night clubs located around the suburb of Kambali.
Document 4: Geography of the United States: West of the Rocky Mountains lies the Intermontane Plateaus (also known as the Intermountain West), a large, arid desert lying between the Rockies and the Cascades and Sierra Nevada ranges. The large southern portion, known as the Great Basin, consists of salt flats, drainage basins, and many small north-south mountain ranges. The Southwest is predominantly a low-lying desert region. A portion known as the Colorado Plateau, centered around the Four Corners region, is considered to have some of the most spectacular scenery in the world. It is accentuated in such national parks as Grand Canyon, Arches, Mesa Verde National Park and Bryce Canyon, among others. Other smaller Intermontane areas include the Columbia Plateau covering eastern Washington, western Idaho and northeast Oregon and the Snake River Plain in Southern Idaho.
Document 5: Cann River: The Cann River rises southwest of Granite Mountain in remote country on the eastern boundary of the Errinundra National Park and flows generally east, then south, then east, then south through the western edge of the Coopracambra National Park and through the Croajingolong National Park, joined by seventeen minor tributaries before reaching its mouth with Bass Strait, at the Tamboon Inlet in the Shire of East Gippsland. The river descends over its course.
Document 6: Karapoti Gorge: Karapoti Gorge is one of the entrances into the Akatarawa Forest, a regional park in the Wellington Region in New Zealand. The Akatarawa River West runs through this narrow, mostly bush-clad gorge towards the Akatarawa Valley. A narrow road winds its way along the steep slopes, providing access for trail biking, mountain biking and walking. Karapoti Gorge is also the starting leg of the annual Karapoti Classic mountain bike event, which runs on the network of tracks in the Akatarawa Forest.
Document 7: Grey District: Grey District in the West Coast Region of New Zealand is a municipality that covers Greymouth, Runanga, Blackball, Cobden and settlements along the Grey River. It has a land area of . The seat of the Grey District Council, the local government authority that administers the district, is at Greymouth, where 27% of the district's population live.
Document 8: Rano Raraku: Rano Raraku is a volcanic crater formed of consolidated volcanic ash, or tuff, and located on the lower slopes of Terevaka in the Rapa Nui National Park on Easter Island in Chile. It was a quarry for about 500 years until the early eighteenth century, and supplied the stone from which about 95% of the island's known monolithic sculptures (moai) were carved. Rano Raraku is a visual record of moai design vocabulary and technological innovation, where 887 moai remain. Rano Raraku is in the World Heritage Site of Rapa Nui National Park and gives its name to one of the seven sections of the park.
Document 9: Marlborough Region: The Marlborough Region, commonly known simply as Marlborough, is one of the regions of New Zealand, located in the northeast of the South Island. Marlborough is a unitary authority, both a region and a district, and its council is located at Blenheim. It has a population of 46,200 (June 2017).
Document 10: Walpole Wilderness Area: The Walpole Wilderness Area is a group of conservation reserves on the south coast of Western Australia. The area includes vast tracts of jarrah, tingle and karri forests surrounding granite peaks, rivers, heathlands, and wetlands. Coastal features include inlets and sandy beaches, sheer cliffs and the Southern Ocean.
Document 11: Greymont: Greymont is a suburb of Johannesburg, South Africa. Greymont is located quite close to both the University of Johannesburg as well as the University of the Witwatersrand, which means it has a rather large number of students living in this area. It is located in Region B of the City of Johannesburg Metropolitan Municipality.
Document 12: Central Coast Regional District: Central Coast Regional District is a regional district in British Columbia, Canada. It has a total land area of 24,559.5 km² (9,482.5 sq mi). When it was created in 1968, it was known as the Ocean Falls Regional District, named for the then-largest town in the region, the company town of Ocean Falls, which has since become a ghost town. The district name was confirmed in 1974, but changed to Central Coast Regional District in 1976.
Document 13: Walker Bay Nature Reserve: Walker Bay Nature Reserve is a nature reserve made up of five areas located on the coast between Hermanus and Cape Agulhas, in the Overberg region in the Western Cape province of South Africa. It is administered by CapeNature.
Document 14: North Island: Twelve main urban areas (half of them officially cities) are in the North Island. From north to south, they are Whangarei, Auckland, Hamilton, Tauranga, Rotorua, Gisborne, New Plymouth, Napier, Hastings, Whanganui, Palmerston North, and Wellington, the capital, located at the south - west extremity of the island. About 77% of New Zealand's population lives in the North Island.
Document 15: Oparara Basin: The Oparara Basin is a basin drained by the Oparara River at north of Karamea, at the West Coast Region of the South Island of New Zealand. With its large natural rock arches, a network of caves rich in fossils, and a beautiful, unspoiled natural environment typical of temperate rainforests, it is one of the most striking places of the Kahurangi National Park. The Oparara Basin is also famous for its unique remains in paleozoology and for being the sole habitat of several plant and animal species.
ground_truth: Greymouth
sub_queries: What is the name of the state where Oparara Basin is located? Answer: West Coast Region
West Coast Region >> capital Answer: Greymouth