This is not the first and I hope not the last of this kind of geocaches I found out there. All you need is a good old Tree with a hole where your container fits easy and won't hang out, a small piece of branch, preferrably same tree to match the colors and texture. Connect the two and plug it in, there you go.

Pulled out a bit for better view.

As you can see this hide was not that difficult as the cache owner did not use the same type of wood to camouflage the hide. We were going all around the tree for a few minutes before I spotted this one, and we were in three.

For the size I added my small pen to the picture, so you see it is no bigger than a nano vial.

I also like using the plastic vials but mostly in urban areas, as this tree was standing by itself on the field it does not take much to suspect the cache is on the tree, but just imagine it was in a forest with bad GPS signal... ok don't even imagine, that would be a sneaky, evil hide.

This is how we found the cache, hiding in its place.

As you can see when it is in its place it is not too easy to spot even with the fact that it is not the same color, as it is not much more in diameter than a centimeter. The good thing about these caches that their location is always trivial, so if you are there and struggle and you are there for an hour already and you message the CO for more hint he could ask you to take a picure of the big branch and he'll check for you if it is there, and that would already be the hint. (I did similar helps before, but my geocache container was unfortunately gone.)

This geocache was part of a trail in the Netherlands with seven traditionals and a bonus. You needed to find all seven to get the coordinates of the bonus.

The tree from a distance, at this time we already knew the geocache is there.

The trail was on a newly established recreational area where you could take a nice walk. Earlier they used to have cows out there, as we learned it from another geocacher doing the same trail. Most of the areas did not yet have the grass grown, there were many trees planted but they were also small, give it a year and the area will look different and nicer for sure.