A large sinkhole has opened up at L'Ancresse on Guernsey's north coast.
The ground gave way next to the Second World War anti-tank wall.
Engineers will begin work next week to fill in the hole, with barriers placed around it until then to prevent anyone from falling in.
Earlier this year, the States revealed its management plan to repair the L'Ancresse wall as it had been falling into disrepair. The repair costs were estimated to be up to £150,000.
Due to the nature of the land in the northern areas of the island, holes are more likely to appear than in other parts of the coastline.
Members of the public are being asked not to go past the barrier or too close to the hole itself.