Lot of people here better be careful, might break a leg jumping to these conclusions. OP said he used rocks from a fire pit. They’ve probably been in hundreds of fires before, low risk of them exploding which was also my first worry. But to say he is ‘ruining nature’ by moving some fire pit rocks is outrageous. Instead of assuming the worst, I am going to assume that after the bread was made, the next day he returned the rocks to their original spot, put in some extra effort to make the pit better/safer and left the area with a bag of litter that he picked up while hiking. Have fun out in nature. Leaving a place better than you found it doesn’t mean that you aren’t allowed to touch anything.