the tunnels measured about 70 cm wide and 100cm in height and were in complete darkness you could not see your hand in front of your face -sooooooo scary, this tunnel was only 7 metres long and there was only one way but I did come to a dead end which threatened to freak me out, a few bottom shuffles back and to the left was the exit - phew. My visit down the tunnel was accompanied by a visit from a bat!!! whose radar wasn't too good or perhaps it was because there was no room because he touched me 4-6 times - I screamed, don't know who was more scared!!!