Hole closes A30 in Cornwall on National Pothole Day
A hole has opened up on the A30 and closed part of the main road through Cornwall on National Pothole Day.
The Highways Agency said the hole was 4ft (1.2m) wide and closed the westbound carriageway near Scorrier.
One lane of the carriageway remains closed as engineers examine the extent of the damage.
A mining expert said it was probably part of an old copper mine and approximately 200-years-old.
The hole, on the verge of the road, is thought to be approximately 15ft (4.5m) deep.
Stuart Dann, director of Mining Eye Ltd, has seen the hole and said: "There's a nice clean wall of rock that tells me that this is the top of a workings site - not a shaft.
"It's the top of an old copper mine and probably about 200-years-old.
"The whole of the area is absolutely riddled with mine workings."
Highways Agency area manager Julian Strong said: "At the moment we do not know what has caused the hole but we are working as quickly as we can to understand what has happened and identify a solution."