As Tim (Shropshire Traveller) hasn't replied, I'll tell you what I think:

No, this is not an annual event, 'though I'd like it to be.

Sixteen adults met up in April, for the first time, in a remote youth hostel (Rowen Y.H.), at the top of a 1-in-3 gradient road, up a mountain, for a hectic weekend of megalithic hunting in North Wales. We all had a great time and some of us are returning at the first opportunity, which is the first weekend in October. We'll be walking for miles over the Tal-y-Fan mountain in the day-time then drinking ourselves silly in the evening, so I don't think it'll be a child-friendly event !

Any adult who feels they'd be up to it is welcome to join us and they'll have happy memories which will last for a long time.

:o)

Baz