I don't do many tree climbing caches so I didn't think I would ever qualify for this challenge. However on June 1st last year we decided to try to FTF the 3 Corners T/D grid Challenge.
Our D1T5 grid corner was "Sweet Colossus" which involved a climb up the largest Sweet Chestnut in Britain. We weren't that confident that we would be able to do it (as we'd failed a month earlier) so we decided to try a smaller tree climbing tree "Up You Go!" as a warm-up. Fortunately we managed both (and successfully completed the other challenge).
When we got home in the evening I started writing up my logs and then suddenly realised I'd done two tree climbing caches that day. I vaguely remembered there was a RubyShoos challenge for that. So I quickly checked the requirements. Had we qualified? No but we were only one off.
There then followed a frantic search for caches with the tree climbing attribute. One that didn't seem too tricky was "Up You Go (Tree Climb)- Eversley". It was starting to get dark when we arrived. A very spindly tree but fortunately it was an easy climb.
Here is a link showing our qualifying caches.
We were in Kent today picking up some puzzles and challenges. By now it was 5pm so we decided to grab this one before braving the M25. It was fairly obvious where to search but there were loads of stingers. It took us about ten minutes to find it.