Since the time of the Firstborn elves and the exodus of the First Men of Ryumar, the world has gradually as a whole been inhabited and conquered by numerous peoples and cultures. It was only at the beginning of the Age of Seas that the world as a whole was greatly explored, and the distance between the various kingdoms, races and cultures slowly but surely became less distant.
Today the many nations and peoples of the world from nearly all the corners of the world interact with each other through means of trade, adventure and, to no lesser importance, conquest through warfare. While the world has become more known, there are still lands yet to be found and explored, and the many dangerous and still mostly unexplored wilds and secrets of the world offer great opportunities for expansion and adventure.
Mages, astronomers and some temples agree that the world is round; based on several factors such as the movement of the sun, creation stories and the cosmological evidence provided by no greater source than the gods themselves. However, there are theories that these are false-facts, again provided by the gods themselves. While many gods have revealed the world to be round, there are those who dispute these claims; mainly the gods who have taken the responsibility for the creation of various things such as the moons or the sun.
Regardless, the majority of students in the world's shape believe that the world is round, and there is otherwise no real reason for it to not be, as many planar worlds and otherworlds are round themselves. But, comparatively, Tariel is a much larger world, and the hope of proving any theories is a bleak venture indeed.