Access to these workings can be tricky, the quickest route is probably via ropes to the beach at Deepgrove Wyke near the southern portal of the Sandsend Tunnel, also check the tide tables before setting off.
There are a series of large cuttings into the base of the cliff, these are then interconnected by a passage running parallel to the shore, the whole cliff is very unstable and should be visited with caution.
The most easterly cutting contains a shelf approximately 6ft high, progressing onto this there are two distinct passages both filled with washed-in debris (including a step ladder) and collapses. The workings are fairly high with plenty of head room.
A high parallel passage runs inside the cliff to the second cutting, however there are no deeper workings behind this entrance.
A waterfall empties over the third large cutting, behind this entrance are again much deeper passages into the cliff.
After about 20m the workings again become clogged with washed-in debris and roof collapses.
I know very little about this, I only picked up on its existence from a Flickr photo. It follows the path which exits the wood so its highly likely its to do with the ironstone mines in Eston.
The track continued in a cutting on the other side of the road, heading off towards Dunsdale, although on closer inspection that is to the north of this area.
A tunnel is marked on this map at Waggonways which also suggest a second tunnel closer to Dunsdale
By way of a disclaimer and warning, its located on a scrambler track (possibly on private land?)
It’s likely unsafe, you’ll get very dirty and need a torch.
*Update 2008* Having visited more mining sites subsequently and spoken to other, I now believe this to be actual ironstone workings rather than a rail tunnel. Its unlined and a bord and pillar arrangement of passages is running parallel to the road not just under it, here are some internal shot taken with a better camera.
One of a number of iron gas lamps that can still be spotted around town, I imagine they will all still be around long after the present round of new street lights are gone too.
UPDATE : In light of this posting I now think its actually a stench pipe from the old drains.
The site of the last fresh water spring in Guisborough, unfortunately doesn’t run any more and is currently full of litter.
Near the end of Fountain Street, where there was a fountain and a lake in front of the original Guisborough Hall on Bow Street which was demolished in 1847.