That entrance that is mentioned that is to the left of the main entrance, I know the one, that was accessable in the late 80's. Now the wooden beam is now just visable and council have back filled it with concrete and stones, pretty much impossible to access. Though you can access it from the main entrance when it was open. The thought of vehicle access is quite right, I read that vehicles would have been coming and going to take the sandstone away just like the tranmere tunnels, though the slope up to the main entrance was made by the fill out of the tunnels.
Main entrance
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The entrance further to the left
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Another cutting in the rock between the main entrance and the entrance with the wooden beam, just a corner of it though but definately man made, probably just storage alcove to stop equipment getting wet.
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