This is a repaired mesh from Level 39 on the Lone Wolf Game. It took a lot to get even this small bit manifold enough to print. I did use Makeitprintable to repair some holes that Solidworks just wouldn't fill.
I scaled it up to be useful for 28mm miniature terrain.
I recommend printing it in parts, and I'm not sure how well the fire pit will turn out even with the split version.