The urban area lies on the central-eastern coast of Otago, surrounding the head of Otago Harbour. The harbour and hills around Dunedin represent the remnants of an extinct volcano. The city suburbs extend out into the surrounding valleys and hills, onto the isthmus of the Otago Peninsula, and along the shores of the Otago Harbour and the Pacific Ocean. Dunedin was the largest New Zealand city by territorial land area until superseded by Auckland on the creation of the Auckland Council in November 2010.