A simple shelf for Figures that can be built out of those hexagonal parts and fit nicely into one Kallax compartment. 

It is designed such that 3 parts in a “row” almost fills the kallax space horizontally (325mm vs 335 mm Kallax) and one can easily fit two rows on top of each other (takes approx 285 mm). 

It has small pins and holes which were supposed to help in positioning for gluing the parts together, but it turned out those are sufficient to hold the thing together without glue (at least for my print).