During the Last Glacial Maximum, sea levels around Motukorea dropped to 100 metres lower than present day levels, meaning Motukorea was surrounded by a vast coastal plain where the Hauraki Gulf / Tīkapa Moana exists today, a part of the forested river valley of the Waitematā (now the Waitematā Harbour.
During the Last Glacial Maximum, sea levels fell by 100 metres compared to current levels, leading to Motukorea being situated on a large coastal plain. This region now comprises the Hauraki Gulf / Tīkapa Moana and the forested Waitematā River Valley.