Althia is a planet roughly the size of Earth, with a similar atmosphere composition and gravity. Althia has no axial tilt, and does not revolve around any other celestial body. It is located in the Material Verge region of the Astral Sea.
Althia's sun, Pelius, orbits around it at a distance of 300,000 miles.
Althia posseses one moon, Seluna. Seluna orbits 200,000 miles above Althia. Seluna is pale white and self-luminous, and undergoes its phases independent from the movements of Althia or Pelius.
In the past Althia was also orbited by Luinor, the divine realm of Sehanine. Luinor was shattered by Lolth in the Dawn War, leaving behind the Ring of Luinor. The Ring of Luinor appears in the night sky as a luminous blue cloud, with sparkling motes of white. The Ring is not visible for most of the day, or when the Seluna is full. The Ring sits 100,000 above Althia at an approximate 45 degree angle from the equator. The Ring is stationary.
Althia sits at the center of Melora's Barrier, a field of anti-magic that cordons Althia off from the Astral Sea. The interior of Melora's Barrier is approximatly 500,000 miles away from Althia. The region of space within the Barrier is the Althian Lacuna.
Althia has two sister worlds, the World Echoes of Feywild and Shadowfell. Feywild is a more vibrant version of Althia, and Shadowfell is a darker version. Both of these worlds orbit Althia outside of Melora's Barrier, at a distance impossible to calculate (distance within the Astral Sea is mutable).
Althia is comprised of seven continents.
Main Article: Lyria
The former domain of the Nerathi Empire, Lyria has played host to numerous great, continent-spanning nations, including the Arkhosian Empire, the High Council of Leng, and the Solmarian Magocracy. Currently the land is divded into several petty kingdoms, many of which are losing ground to the wilds.
Main Article: Fricana
A diverse, extreme land, Fricana is home to the Hatari Jungle and the Ah-Aman desert, as well as the great savannahs that stretch in betwen. Fricana is home to the Liontuar Pridelands, as well as the Dahab Caliphate.
The most cultured and sophisticated land in Althia, Mandara is home to several advanced empires and nations, most of which claim descent from the fallen Empire of Bael-Turath.
Full of humid jungles and rolling plains, Zhakala is divided almost equally between the Zannadi Empire of the Yuan-ti, and the Elven nations. The two sides are locked in an unending cold war. Zhakala is also home of the Haven, the Warforged city.
A land thus far untouched by foreigners, Knaya is the home of the Rhox nations, and the lost tribes of the Elves. Little is known about this contitent.
The northern pole, Felden is dominated by the Dwarven Kingdoms. It is cold and forbidding, and most settlements are built underground. The last remnant of the High Council of Leng resides here in the Mountains of Leng. Felden is also the location of the legendary Dawnspire.
The southern pole, Oerden is largely uncharted. It is home to several Goliath tribes, about which little is known.
Althia has three major oceans, the Ocean of Wrath, Ocean of Songs, and the Ocean Unending. There are also several seas, including the Prismatic Sea, the Sea of Sirens, and the Sea of Treachery. The oceans are home to several aquatic civilizations, most notably the Darfellan nations and Sahuagin tyrannies.
A region beneath the crust of Althia, the Underdark is a complex of caverns and tunnels that run deep into the heart of the planet. The Underdark is the realm of the Dwarves, Drow, Duergar, Illithids, and Aboleths. In the Dawn War the god Torog was bound here. The Underdark is the most mysterious place in Althia, and even its inhabitants haven't mapped it all.
Althia was created before the Dawn War by the Primordials, with aid from the Far Realms. Althia was called Axis by the Primordials, as it lay at the center of universe.
Althia was created as a place for Primordials to undergo the Great Work, a process that they hoped would lead to the perfection of the physical elements. Soon after the Primodials created Althia it was invaded by the Gods, who claimed it as their own.
For much of its early history Althia was the battleground of the Gods and Primordials, and the planet suffered greatly under their wars. Only with the raising of Melora's Barrier has Althia finally been made safe and stable.