We're waiting with bated breath! Get on with it!
... actually, a significant amount of Othard's geography can sort of be gleaned from the Xaela tribe descriptions.
Aside from Doma, which is probably (or rather was probably) an island nation off the Eastern coast...
In the north is a great mountain range and glaciers. In the south of the continent is a great desert, on the northern border of which is a system of limestone caverns. There is a coast in the east, as well as another (the same?) mountain range the Raen hail from. The west seems to be a vast steppe (grassland). A great river splits the steppe in half, running (presumably) from north to south. Wild animals include tigers and horses (not horse-birds).
Ryuji got the rest.