 Westminster Abbey and the Palace of Westminster (commonly known today as the Houses of Parliament) were built on Thorney Island, which used to be an eyot.Researchers have identified the River Thames as a discrete drainage line flowing as early as 58 million years ago, in the Thanetian stage of the late Palaeocene epoch.Until around 500,000 years ago, the Thames flowed on its existing course through what is now Oxfordshire, before turning to the north-east through Hertfordshire and East Anglia and reaching the North Sea near present-day Ipswich.