Here's what's significant about them:
* Magical Origin: The runes were inscribed by the dwarves and possess a magical quality. They only become visible under specific conditions.
* Revealed by the Fire: The runes on the map are hidden until exposed to fire or heat. This acts as a safety measure, ensuring only those with fire (and likely intent on using the map) can see the hidden paths.
* Mapping the Secret Way: The runes reveal a secret passage through the Misty Mountains, allowing the dwarves to avoid the dreaded Goblins and their treacherous paths.
The runes, therefore, are a crucial element in the story, adding an element of mystery, danger, and intrigue to the adventure. They also showcase the dwarves' craftsmanship and their understanding of ancient magic.