Beach clean-up days are held regularly on Gower

The National Trust has said the problem at Three Cliffs Bay on Gower was caused by people dropping litter, camping illegally and lighting fires.

The Trust said the situation at the beach needed to be addressed.

Spokesman Mike James added: "People who have visited Three Cliffs recently have been alarmed at the damage caused."

He added: "It has been an increasing problem in the last few years.

"We get a lot of visitors across Gower but, for a lot of local students, it seems to be an annual ritual to target Three Cliffs Bay in particular.

Some inconsiderate visitors are damaging this fragile environment Sian Jones, National Trust

"It is mainly litter. Bottles and cans are left where there have been parties in the night - this is left for families who arrive the next day."

Mr James said keeping the area clean and protecting it for future generations was "a constant battle".

The Trust, which owns and manages three-quarters of the Gower peninsula, said local residents and volunteers had also faced verbal abuse from some visitors.

'Unspoilt beauty'

The recent spell of good weather has brought increased numbers of people to the coastline, making the environmental problem worse.

Sian Jones, the National Trust's Property Manager on Gower said: "People love coming here for its unspoilt beauty, for peace and quiet, for relaxing and for memorable days out with the family.

"But some inconsiderate visitors are damaging this fragile environment."

In 1956, the Gower peninsula was the first area in the UK to be designated an Area of Outstanding Natural Beauty.