The Arch of Fire

Not a settled realm but a war zone: a volcanic waste in the northeastern Icereach Range, where the twin Mount Cantrinus volcanoes throw up a burning arch said to be a route to the Plane of Fire [Alm-ArchFire] [CM1] [MMB-Region]. Two peoples of fire contest it.

Terrain

A flat volcanic plain of lava streams, meltwater lakes, and steam geysers, maybe 5,000 square miles, between the White Bear River swamp and the Icereach peaks. The fiery arch rises four to six miles and spans some four days’ walk; it is visible from seventy miles off [Alm-ArchFire] [Neri-TG]. Leeha lies 15-20 days’ travel east [Alm-ArchFire].

The situation

The efreet stronghold is lethal to approach. The Sun Brothers are gathering their scattered order from across Mystara and need allies [Alm-ArchFire]. For a party, the Arch is a high-tier objective (the efreet are a serious army) and a recurring threat on the western horizon: a holy war a DM can let simmer for a dozen levels and then light.