Places you've been and their real-world analogue locations:
Shatterspine Mountain Range: Appalachian Mountains
The Sea of Trees: West of the Appalachian Mountains, up and down the Kentucky/Tennessee area of America
Valetto: Georgia roughly represents the size and area of President Coghammer's domain
St. Agnes = Atlanta
The Devil's Cauldron: Evansville, IN
Tollerhelm: Tuscaloosa, AL
