Both the planet and the continent on which the campaign takes place.
The setting: Ancient Persia lookalike. A rugged land, mountainous and scrubby.
The Big Religion: A Zoroastrian knock off, with an emphasis on truth telling. The priests have spells to determine honesty. Lies are severely punished.
MAGICS: Recently imported from India pastiche.
All ocean water is poison. All fresh water is antidote to said poison. What happens at the river deltas where the two meet?
There exist great plains filled with nothing but metal shavings that explode on contact with living beings. The moto-golems have no trouble traversing them, and indeed, sometimes track fragments of the shavings into settlements, which can prove hazardous until removed.
There are airships connecting civilized nations controlled by powerful transportation guilds.