Ironbridge Gorge bore holes check old mine workings
Bore holes have been drilled to detect old mine workings as part of project to stabilise land around the Ironbridge Gorge World Heritage Site.
Roads at Jiggers Bank were closed in November after landslips following heavy rain.
The bore holes are also being used to test and monitor ground movement, according to Telford and Wrekin Council.
Jiggers Bank is expected to remain closed until June.
The council said work has been concentrated in Jackfield between the Tile Museum and the Boat Inn - an area that has suffered significant landslides in the past.
The Jackfield Stabilisation Project aims to allow a new highway to be built on the stabilised ground.
The scheme will involve earthworks, the treatment of mine workings, river bank protection, drainage improvements, highway construction and landscaping, a spokesperson said.
The council said stabilisation works would need to be completed in early 2016 due to the funding secured from central government.
Councillor Richard Overton said: "Since 2001, Telford and Wrekin Council has spent more than £16m on tackling land instability in the gorge.
"This, combined with £12m government funding, is enabling us to carry out this complex technical project."