Dorset County Council said they are now checking the structure of Beaminster Tunnel in Dorset.
It's parapet was destroyed in a landslide caused by heavy rain.
The Council said they will need to tackle the drainage before they address the stonework.
Beaminster Tunnel is expected to remain closed until the 22nd July.
More top news
Cornwall have retained their County Championship title beating Cheshire at Twickenham.
Exeter Chiefs refuse to be too downhearted after losing their first Premiership rugby final to Saracens.
Thousands of rugby fans made the journey to Twickenham today to see the Exeter Chiefs take on Saracens.