Northern Slope Mine is a mine located in the Impossible Mountain Range that is next to Border Town.
The Northern Slope Mine was originally made to excavate God's Stones of Retaliation. It was later made into a mine to provide ores to Longsong Stronghold.
At the beginning of the story it was only a small town, but with the help of steam engines it was reformed.
The Northern Slope Mine is located at the entrance of a huge network of caves and tunnels. The end of this network was not discovered even as Sylvie explored it. Instead she discovered a huge amount of Gods Punishment stones.