GeoGraph - photograph every grid square

Barrier across River Burn estuary

This is a curious phenomenon to which there may a simple explanation: human intervention. This line of rocks seems geologically alien to the area but neatly bars the outfall of the river that comes out from Burnham Overy Staithe. This is the view at low tide. Compare TF8445 : Barrier across River Burn estuary. In recent times, the river did not emerge by this route but further east, as shown on the OS maps. Were these rocks an attempt to turn it, or keep it turned, eastwards ? In the background is Gun Hill.