Looking over the harbour waters and southern side of the Otago Peninsula from Mt Cargill road.br/br/The Otago Peninsula is a long, hilly indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the eroded valley that now forms Otago Harbour. The peninsula lies south-east of Otago Harbour and runs parallel to the mainland for 20#160;km, with a maximum width of 9#160;km. It is joined to the mainland at the south-west end by a narrow isthmus about 1.5#160;km wide.