The plane of Dawn is spherical, surrounded by the Aetherial Barrier, separating the plane of Dawn with the endless plane of the Aether. Around 1,500 miles beneath the surface of Dawn, another barrier, the Abyssal Barrier, exists. This barrier, although much weaker, seperates Dawn from the infernal Abyss. The Abyss isn't technically part of the plane Dawn, therefore it is much larger than logically possible (having an estimated total volume of 700,00 million miles). This, obviously, could not fit in a planet only 3,000 miles deep.
Dawn's total surface area is slightly under 38,500,000 (38.5 million) miles, having a diameter of 3500 miles and being 3,000 miles deep.
Because the mortal children of the Gods could not see, for there was eternal darkness, the Goddess of Heat, Pyrava, created the Sun, a sphere of magic twisted with the Goddess' very life force. This "sun" rotated through the Aether, but was bright enough and warm enough to light and warm Dawn, but the gift was only given once a day for half the day on each side of the world. While Belden , Namis, and Saelonthor shined with the light of the sun, darkness flooded Erayus, Talo, and the eastern half of Raxus. The sun shined directly above a line known as the "equator", where everything was warmer and the farther from this virtual line you were, the colder it was. Therefore, places directly on the "equator", like Belden and central Erayus and Talo were much warmer than the Tudric lands of Namis and Saelonthor.
Most of the area around the equator are very dry deserts. As you move south, swamps dominate the landscapes, while if you move north, you encounter grasslands then tundras. Places like Erayus and Talo stretch across the surface of Dawn, housing all of these different climates.