The wood is from Jake (badcopnofish) here on TPT. Several months ago I asked him to send me a big box of wood with various sizes. It's nice to have lots of spare pieces laying around for projects. The wood on the left is 3 individual pieces. 1 on the ground with anubias attached. The other two start behind the rock in the corner.
The middle piece just rests on the planter box, the upper piece is held in place with zipties attached the the PVC that feeds fresh water from the filter into the cave. This isn't the best pic, but you can kind of see the outline of the 2 zipties. I superglued a piece of java fern to the lower ziptie to hide it once it grows in. Even in person, it's hard to see the zipties unless you know where to look.
On the right side, there is basically 2 pieces. The smaller piece (in blue) appears to come forward over the rock like a root. The second piece (in green) is a very large piece that splits three times with 2 of the parts appearing to grow straight up. You can see it best in this older pic just after setup.
Here's today's pic for comparison.