Thanks for the replies chaps. It looks like we should do a little more exploring around that end of the campsite to see what we can find!
Cheers, Neil.

Just after a bit of info re access to Houx.  I'm not sure exactly which way is north, but....
if we consider the main vehicular entrance/exit is at the east end of the campsite, I know that there is access to the track via the footbridge to the north of the campsite behind the cafe and showerblock, but it is quite a long walk to the pit straight from there. Is there also pedestrian access to the circuit from the west end of the campsite?  I remember seeing a new tunnel behind the pits last year but we didn't get a chance to try it. Any chance it can be used to get to Houx...it would be a lot quicker than walking round?

Cheers, Neil.