Ymirea is thought to be a great disk under the vault of the heavens. This disk has definite edges, hedged with mountains in some places, in other places the ocean falls wildly over the edge into the outer waste. It is said that in the far Occident, humans live near to the world's edge. What lies beyond the edges of the world, no-one knows, though some say an infinite sea, others a great void, still others claim that other worldspheres lie next to the Ymirean one.
To the north of the Disc is Boreas, the giant frost, blowing cold winds southwards. To the south of the disk is Auster, the giant fire, blowing hot winds northwards.
The disk has several landmasses, and one great body of water traditionally divided into a number of oceans.
In the centre of the world, there is a great mountain, called the Mount Omphalos, around this is the continent Terra Centralis.
Cargandom (the "civilized world" of all campaigns set in Ymirea so far) is found on the northernmost part of the Terra Centralis, and on the south-western part of Terra Borealis (the continent north of Terra Centralis)