The world that Alchemy Stars takes place in. One side of the world is perpetual daylight, and the other side of the world is perpetual night. It is discussed in Ada and the Colossus IV.
Astra[]
Astra is the main continent that the story takes place in on Eoria, largely due to the fact that it is right at the precipice of where the world is split between eternal day and eternal night, allowing it to have a normal day and night cycle.