The River Torrens runs largely westward from the Adelaide Hills, through the centre of Adelaide to the Gulf St Vincent. It originates close to the eastern fault scarp of the Mount Lofty Ranges, near Mount Pleasant, approximately above sea level. It runs predominantly along faulted north-south ground structures, which were formed over 250 million years ago during the Paleozoic era then further dislocated during the Cretaceous and earliest Tertiary. There is a subsidence along the Para Fault which also affects the rivers flow. This subsidence was formed in the last two million years, after the Pliocene era.