A further cliff collapse happened at Mawgan Porth Beach on Wednesday.
A sizeable section of the cliff came away and landed by the cave on the north side of the beach.
It follows a “substantial” cliff collapse in the same area on New Year’s Day.
Newquay Coastguard Search and Rescue Team is urging people to keep a safe distance.
A Newquay Coastguard spokesperson said: “There has been another sizeable section of cliff collapse by the cave on the north side of Mawgan Porth Beach overnight.
“The public are reminded that this area remains hazardous and to maintain a safe distance.”