HUGE waves washed away part of the road between two North Cornwall villages on Monday night.
Residents in Port Gaverne have been cut off from driving to nearby Port Isaac because of the landslip.
The waves destroyed a retaining wall and undermined part of the road between the two villages.
The road is expected to be closed for a considerable time.
The police and Cornwall Council Highways staff were called to the scene on Monday night, and put up road blocks to close off the road to motorists.
Richard Cook lives in a house next to where the road gave way. He said: "It all happened between 6.30pm and 7.30pm on Monday when the retaining wall gave way.
"I'm letting people use my drive because it's the only way through for pedestrians.
"With the road closed, it means that if anyone wants to get to the Co-op, a quarter of a mile up the road, they now have to travel about six miles via Pendoggett to reach it.
"People from Highways came out on Monday night to take a look at the damage and went away again, but when the road can be repaired is anyone's guess," said Mr Cook.
Police said the road had been closed as a matter of public safety.
"People won't be allowed to use it and will have to find alternatives between Port Isaac and Port Gaverne," said PC Malcolm Taylor.