Caves opposite Tintagel Castle
Coastline around Bossiney
You can explore this stretch of coastline from either Trebarwith Strand or Tintagel Haven (Castle Beach). From Trebarwith Stand you can paddle out to Gull Rock in 5-10 min or left past Dennis Point to Backways Cove and Tregardock.
If you head right from Trebarwith Strand past Penhallick point it's about an hour's leisurely paddle to Tintagel castle. In between Penhallic point and the castle is a HUGE sea cave which you can paddle inside at high tide (NB only attempt this if there is no swell) - take a torch.
There are also some sea caves in the side of Barras Nose, just out from Tintagel Haven. Grey seals may have pups in these caves in the Autumn - don't get to close if they do as you might get chased off by a protective mother. From Tintagel Haven, in about an hour you can paddle round Barras Nose and Willapark to Bossiney Haven and Benoath Cove and where Rocky Valley meets the sea and in about another half an hour to the rock stacks at Trevalga.