 Flint from these early mines played a significant role in enabling the "Neolithic Revolution" to take place across southern Britain, gradually replacing the nomadic hunter-gatherer way of life of the mesolithic period with the settled agricultural way of life of the neolithic period as the extensive wildwood forest that covered much of Britain began to be felled.There is evidence that flint from the mines around Worthing was traded across southern Britain, particularly to the populous areas on the Wessex downland.The flint mines were at Harrow Hill in Patching (mined from 4250 BC to 3500 BC), Blackpatch Hill in Clapham (4350 BC to 3500 BC), Church Hill in Findon (4500 BC to 3750 BC)— all outside the present borough of Worthing—and Cissbury, which is within the borough and which had between 100 and 200 mineshafts, making it Britain's second largest after Grimes Graves in Norfolk.