Hollow World is a world campaign supplement written specifically for Dungeons & Dragons.
This detailed campaign module proposes that within the sphere of the "Known World" is another world called the Hollow World, a sub-setting for the Mystara campaign world. Hollow World acts as a living "cultural museum" for the planet, forever preserving cultures and races that are near extinction on the surface world.
This box set includes the following:
A 128-page softbound Dungeon Master's Sourcebook
A 64-page softbound Player's Guide book
A 32-page softbound Adventure Book
Four single-sided poster maps
The books include information about new monsters, elves, dwarves, character classes, pirates, and immortals.
Outer-World, Postcataclysmic Map / Outer-World, Precataclysmic Map / Hollow World Diagram (poster-sized, single-sided, full color)
Outer-World Planetary Map / Hollow World Planetary Map / Outer-World Arctic Cap / Outer-World Antarctic Cap / Hollow World Arctic Cap / Hollow World Antarctic Cap (poster-sized, single-sided, full color)
Northern Iciria (poster-sized, single-sided, full color)
Southern Iciria (poster-sized, single-sided, full color)