UPDATE: CORMAC has been on site today and concrete has been poured into the hole which will be left to harden until Wednesday, when it is intended to reopen the road to single file traffic.  On Thursday evening, the plan is to reopen the road to two way traffic.

A hole that opened up on a West Cornwall road is thought to be related to Wheal Rodney, a copper mine that was used from 1824 to 1848

Gwallon Lane in Marazion was closed from the top of Shop Hill this weekend following the appearance of a hole in the road, with CORMAC staff securing the site with two rings of fencing. 

The void is greater than 3.5m deep and approximately 1.6m in diameter.  It is unclear whether this is a working from underground that has broken through to surface, or whether it is a shaft on a known lode that crosses the road at this location.

A spokesman said: "Although the hole appears relatively small at surface, it’s extent below surface remains unknown at present. The possibility of either collapse of the carriageway into the existing void, or unknown workings extending below the highway cannot be ruled out at this stage.

"Public safety is the greatest concern, and until plant and materials are in place on Monday morning to investigate and remediate the mine feature, the road will need to remain closed.