Lalaria, on Skiathos’s northern coast, Greece.

Tourists are being urged to return pebbles taken as souvenirs from a picturesque Greek beach where Abba musical Mamma Mia! was filmed.

Officials on the island of Skiathos have taken action to prevent the beach from being stripped bare. This week boxes bearing the words ‘Lalaria Beach return box’ appeared at Skiathos airport after campaigners said the stones were disappearing at an alarming rate.

Tourists found pocketing pebbles can now be fined up to 1,000 euros (R17,000) under a new law.

Thodoris Tzoumas, head of the island’s cultural association, said: ‘We had no other choice. Lalaria may not have suffered a landslide but human intervention is such that its natural beauty is being destroyed at an alarming rate.’ Posters have been pinned up on cruise boats and a billboard on the beach asks holidaymakers to ‘take a picture not a pebble’.

Lalaria, on Skiathos’s northern coast, grew popular in the 1970s when Greek officials put its crystal clear waters front and centre of tourism campaigns.

It became world-renowned after it was used as one of the locations for the first Mamma Mia! film in 2008. This summer’s release of sequel Mamma Mia! Here We Go Again sparked a new wave of tourists and weddings that threaten to overrun the island.

The cultural association says the beach’s larger pebbles have almost entirely disappeared.

But Mr Tzoumas said the return boxes at the airport appeared to be working. ‘We’ve been pleasantly surprised,’ he said. ‘They have only been there a few days and they are beginning to fill up.’

© Daily Mail