Cliff collapses at Welsh beach as people urged to avoid the areaTonnes of rock and debris crashed onto the sand at Porth Swtan in a dramatic landslip filmed by a local residentView 2 Images Yesterday morning's landslip. Massive amounts of rock and debris plummeted onto the shore at Porth Swtan (Church Bay), Anglesey. Continuous weathering of the cliff face has now reached dangerously near to the island's coastal walkway. Through a social media post, the authority urged visitors to "avoid the area". Hard defences are deemed "unsustainable", risking damage to the beach that provides a natural form of defence.