These geometric patterns are carved into a sandstone cliff at Blackstone Rock near Bewdley, Worcestershire. The hexafoil or daisy wheel is commonly seen as a "witch mark", an apotropaic symbol marked on buildings - and occasionally boats - to protect against sorcery.
This is often true but the symbol has been in use within many religious contexts since the Bronze Age. I have no idea who carved the patterns at Blackstone Rock or why, but it seems appropriate as the cliffside hermitage where monks lived in caves stands just across a nearby field.
The track along the river is well-worn, having served monks, pilgrims, boat crews and river people for a thousand years.