In reply to pete123:
The routes were originally done by members of the Clyde Valley MC about 40 years ago.I did have the names of the guys but have long forgotten them.
There used to be a couple of dodgy old pegs there as well.
There are a lot of stories floating around about who originally done the carvings but the truth is it was local guy from Blantyre and they are of relatively recent origin.They are a bit naff but I like them.
The tunnel story has been floating around for years and a quick Google will find you the truth
I agree with JLS and top roping only.There is a good route on the castle walls as well but I didn`t tell you that !
There are also some short chipped routes of varying standards under the big bridge in Larkhall though I think JLS and Gavin were down a few years ago and thought it may have been banned or something.