I first drew this (with pencil and paper) late at night, before I turned off the light to try and get some sleep. I liked the look of it, but I myself deemed it un-impossible, in other words, possible. It wasn’t until I redrew it weeks later and studied it closer that I realized that it was indeed impossible, so here it is! It still takes a bit of work to wrap your head around it.
To see why this figure is impossible, compare the two different sides. If you follow both the top and bottom beams, you will notice that the ends will not match up.