 The suburb consists of most of the southern half of the Rongotai isthmus, although Wellington International Airport and a small industrial area next to it are often considered to be part of Rongotai.Lyall Bay was probably the ancient mouth of the Hutt River.The current isthmus was created by geologic upheaval as result of recurring earthquakes, the most recent occurrence being the 1855 Wairarapa earthquake.