Question: Summertown is a town in the Adelaide Hills region of South Australia, in which country?

full_context: Document 1: Geology of South Australia: South Australia is an Australian state, situated in the southern central part of the country, and featuring some low-lying mountain ranges, the most significant being the Mount Lofty Ranges, which extend into the state's capital city, Adelaide, which comprises most of the state's population. Adelaide is situated on the eastern shores of Gulf St Vincent, on the Adelaide Plains, north of the Fleurieu Peninsula, between Gulf St Vincent and the low-lying Mount Lofty Ranges. The state of South Australia, which stretches along the coast of the continent and has boundaries with every other state in Australia, with the exception of the Australian Capital Territory and Tasmania. The Western Australia border has a history with South Australia, involving the South Australian Government Astronomer, Dodwell and the Western Australian Government Astronomer, Curlewis in the 1920s to mark the border on the ground.
Document 2: Lobethal: Lobethal is a town in the Adelaide Hills area of South Australia. It is located in the Adelaide Hills Council local government area, and is nestled on the banks of a creek between the hills and up the sides of the valley. It was once the centre of the Adelaide Hills wool processing industry, which continued until around 1950. The mill buildings are now used by a number of cottage industry and handcraft businesses. At the 2006 census, Lobethal had a population of 1,836 which had grown to 1957 by the 2011 census.
Document 3: Mount Lofty Botanic Garden: First opened in 1977, the crescent-shaped Mount Lofty Botanic Garden is situated on 97 hectares on the eastern slopes of Mount Lofty in the Adelaide Hills east of Adelaide in South Australia. The cooler, wetter location suits plants from temperate climates which are difficult to grow on the Adelaide Plains. Amongst the native Australian flora there are tree ferns, as well as exotic cultivated plants from cool climates including Rhododendron and Magnolia and the National Species Rose Collection. The Mount Lofty Botanic Garden, together with the Adelaide and Wittunga Botanic Gardens, is administered by the Botanic Gardens of South Australia, a State Government statutory authority.
Document 4: Greenhill, South Australia: Greenhill is a suburb of Adelaide located about 9.3 km east of the city centre in the foothills of the Adelaide Hills. Its boundaries were created in October 2001 in respect of the “long established name” with some land being moved into the adjoining suburb of Waterfall Gully in July 2002. The suburb includes Greenhill Recreation Park and the western slopes of Mount Lofty. Greenhill Creek flows through Waterfall Gully and feeds into First Creek.
Document 5: Mount Lofty Ranges zone (wine): Mount Lofty Ranges zone is a wine zone located in central South Australia west of the Murray River that occupies the Adelaide metropolitan area north of Glenelg, extending as far north as Crystal Brook, and as far south as Mount Compass in the Mount Lofty Ranges. The zone which encloses the Barossa zone on three sides, consists of the following wine regions all of which have received appellation as an Australian Geographical Indication (AGI): Adelaide Hills, Adelaide Plains and Clare Valley. The zone received AGI in 1996.
Document 6: Mount Osmond, South Australia: Mount Osmond is a small suburb of 2,497 people in the South Australian capital city of Adelaide. It is part of the City of Burnside local government area and located in the foothills of the Adelaide Hills, five kilometres south east of the city centre. The suburb is high on the hill of the same name, which is the last hill on the right when approaching Adelaide down the South Eastern Freeway before the road levels out onto the Adelaide Plains. It is bounded to the north by the suburb of Beaumont, to the north-east by Burnside, to the east by Waterfall Gully, to the south by Leawood Gardens/Eagle On The Hill, to the south-west by Urrbrae, to the west by Glen Osmond and to the north-west by St Georges.
Document 7: Mount Torrens, South Australia: Mount Torrens is a town in the eastern Adelaide Hills region of South Australia, 46 kilometres east-north-east of the state capital, Adelaide and 8 km east of Lobethal along the Onkaparinga River. It is located in the Adelaide Hills Council local government area. At the 2006 census, Mount Torrens had a population of 337.
Document 8: Onkaparinga Hills, South Australia: Onkaparinga Hills is a southern suburb of Adelaide, in the City of Onkaparinga. It covers an area of approximately 22 km2 . It has a population of 2534 people (2011 Census). It is a leafy suburb that includes parts of the Onkaparinga River National Park.
Document 9: City of Campbelltown (South Australia): The City of Campbelltown is a local government area in the north eastern suburbs of Adelaide, South Australia about 6 kilometres from the Adelaide GPO. The City is bordered by the River Torrens and the City of Tea Tree Gully, the District of Adelaide Hills, the City of Burnside, the City of Norwood Payneham St Peters, and the City of Port Adelaide Enfield. The City has an estimated population of 51,889 people.
Document 10: Adelaide Hills: The Adelaide Hills are part of the Mount Lofty Ranges, east of the city of Adelaide in the state of South Australia. It is unofficially centred on the largest town in the area, Mount Barker, which has a population of around 29,000 and is also one of Australia's fastest growing towns.
Document 11: Adelaide Hills Council: Adelaide Hills Council is a local government area in the Adelaide Hills of South Australia. It is in the hills east of Adelaide, the capital of South Australia, and extends from the South Para Reservoir in the north to the Mount Bold Reservoir in the south.
Document 12: Summertown, South Australia: Summertown is a town in the Adelaide Hills region of South Australia. It adjoins Uraidla. At the 2006 census , Summertown had a population of 392.
Document 13: Mount Torrens, South Australia: Mount Torrens is a town in the eastern Adelaide Hills region of South Australia, 46 kilometres east-north-east of the state capital, Adelaide and 8 km east of Lobethal along the Onkaparinga River. It is located in the Adelaide Hills Council local government area. At the 2006 census, Mount Torrens had a population of 337.
Document 14: Mount Lofty: Mount Lofty ( , elevation 727 metres AHD) is the highest point in the southern Mount Lofty Ranges. It is located about 15 km east of the Adelaide city centre in South Australia, and has panoramic views of the city and the Adelaide plains to the west, and of the Picadilly Valley to the east.
Document 15: Eagle On The Hill, South Australia: Eagle On The Hill is an unbounded locality of Adelaide in the Adelaide Foothills. It borders Mount Osmond and Waterfall Gully.
ground_truth: Australia