Context_1 : Birkenhead is a north-western suburb of Adelaide 14 km from the CBD, on the Lefevre Peninsula, in the state of South Australia, Australia, and lies within the City of Port Adelaide Enfield. It is adjacent to Peterhead, Exeter and Glanville. It is bounded to the south by the Gawler Reach of the Port River, to the north by Hargrave Street and in the west and east by the Outer Harbor railway line and the Port River respectively. Context_2 : Angle Park is a north-western suburb of Adelaide 10 km from the CBD, in the state of South Australia, Australia and falls under the City of Port Adelaide Enfield. It is adjacent to Wingfield, Mansfield Park, Ferryden Park, and Regency Park. The post code for Angle Park is 5010. It is bounded to the north by Grand Junction Road, west by Trafford Street, and to the east by Days Road and the North-South Motorway. Context_3 : Woodville North is a north-western suburb of Adelaide 10 km from the Adelaide city centre, in the state of South Australia, Australia and falls under the City of Charles Sturt. The post code for Woodville North is 5012. It is adjacent to Pennington, Athol Park, Woodville Gardens, Mansfield Park, Woodville and Kilkenny. It is bordered to the east by Hanson Road to the west by Carlton Crescent, to the south by Torrens Road and to the north by Hamilton Road. The suburb is residential, apart from an industrial pocket to the northwest. Context_4 : Ethelton is a north-western suburb of Adelaide 13 km from the CBD, on the LeFevre Peninsula, in the state of South Australia, Australia and is within the City of Port Adelaide Enfield. It is adjacent to Semaphore, Semaphore South and Glanville. It is bounded to the north by Hart Street, to the south by Bower Road and in the west and east by the Swan Terrace and the Port River, respectively. Context_5 : Ferryden Park (postcode 5010) is a north-western suburb of Adelaide 9 km from the central business district, in the state of South Australia, Australia. Situated in the City of Port Adelaide Enfield local government area, it is adjacent to Kilkenny, Angle Park, Woodville Gardens, Croydon Park, and Regency Park. It is bounded to the north by Murray Street, west by Liberty Grove and Hassell Street, south by Regency Road and to the east by Days Road. Context_6 : Woodville Gardens is a north-western suburb of Adelaide 9 km from the CBD, in the state of South Australia, Australia and falls under the City of Port Adelaide Enfield. It is adjacent to Woodville North, Mansfield Park, Ferryden Park, and Kilkenny. The post code for Woodville Gardens is 5012. It is bounded to the south by First Avenue, and to the east by Liberty Grove, and to the west by Hanson Road. Context_7 : Gillman is a north-western suburb of Adelaide, in the City of Port Adelaide Enfield. It is located within the federal division of Port Adelaide and the state electoral district of Port Adelaide. Context_8 : Mansfield Park is a north-western suburb of Adelaide 10 km from the CBD, in the state of South Australia, Australia and falls under the City of Port Adelaide Enfield. It is adjacent to Wingfield, Angle Park, Woodville Gardens, and Athol Park. The postcode for Mansfield Park is 5012. It is bounded to the north by Grand Junction Road, and to the west by Hanson Road. It is named after the Mansfield in East Ayrshire, Scotland. Context_9 : The City of Port Adelaide Enfield, located across inner north and north-western suburbs of Adelaide, is one of the largest metropolitan councils within South Australia. It was established on 26 March 1996 by the amalgamation of the City of Port Adelaide and the City of Enfield. Context_10 : Croydon Park is a north-western suburb of Adelaide 7 km from the CBD, in the state of South Australia, Australia and is within the City of Port Adelaide Enfield. It is adjacent to Dudley Park, Devon Park, Renown Park, Regency Park, Ferryden Park Kilkenny, and West Croydon. The post code for Croydon Park is 5008. It is bounded to the south by Lamont Street and Torrens Road, to the north by Regency Road and in the east and west by Harrison Road and Goodall Avenue respectively. Croydon Park is predominantly a residential suburb, with a warehousing presence on the northern edges near Regency Road. fact_1 : Birkenhead is a north-western suburb of Adelaide 14 km from the CBD, on the Lefevre Peninsula, in the state of South Australia, Australia, and lies within the City of Port Adelaide Enfield. fact_2 :  It was established on 26 March 1996 by the amalgamation of the City of Port Adelaide and the City of Enfield. Answer: Birkenhead
Output: Which northwestern suburb of Adelaide lies within a territory which was established on 26 March 1996?