I like to build houses on top of them. The fire can go right on the top of the stone. The house can spiral around it for a few levels. Since it's up off of the ground, and since the rock it's on can't be destroyed, it's fairly secure and just neat looking.

I do dig a ditch around the outside to keep trolls a safe distance away, which mean that the defense properties of the stones themselves aren't really needed, but it's fun anyway.

https://steamcommunity.com/sharedfiles/filedetails/?id=2535141792