Half a million years ago the River Thames flowed on its existing course through Oxfordshire, but then turned northeast to flow through Hertfordshire before eventually reaching the North Sea in East Anglia near Ipswich. At the end of the last ice age the amounts of melt water entering the Thames caused it to cut a new route through the chalk at the site of the Goring Gap. The newly formed route flowed through Berkshire and present day London before finally reaching the North Sea.
Today, the Goring Gap constricts the River Thames narrowing the otherwise broad river valley. Steep hills rise southwards to Lardon Chase, the nearest section of the Berkshire Downs while the Chiltern Hills rise to the north. The twin villages of Goring and Streatley straddle the River Thames at the Goring Gap.
The Goring Gap represents an important communications and transportation corridor accommodating a major road connecting Reading to Oxford along with the principal railway line west from London (Paddington).
- Michael J Crawley. "Geology and Soils" (PDF). Imperial College. Retrieved March 21, 2007.