The image was shared by a community Facebook page alongside a warning about the cliffs.
The Friends of Portheras Cove, named after the beach near St Just, Cornwall, said a number of people, including the family, had been risking their lives unknowingly and people should be more aware of the dangerous cliffs.
They shared the images last week, after boulders fell onto the beach.
In one of the pictures, children can be seen close to the base of the cliffs and in another, a man has scaled part of the cliff to retrieve his kite.
A spokesperson for Friends of Portheras Cove said: "Please be aware that the cliff-faces at Portheras and Boat Cove are unstable and rocks and boulders fall down regularly.
"Keeping away from the areas at the base of the cliffs is advised at all times. Behaving irresponsibly, as the people in these photos are doing, is quite astonishing.
"Heed the warning signs - we do not want to be finding the horrific consequences of this foolishness... litter is bad enough".