The Serion is a major desert that covers much of northeastern Tarephia. While there is not a clearly defined border, it is technically separate from the even larger Great Helion Desert, which covers the northwestern part of the continent.
Countries that include portions of the Serion include, from northwest to southeast: Merracos, Al-Kaza, TA026c, Augustina, TA017a, TA025, Pohenicia, Ulifax, TA022b, Sirrhae, TA031, TA023, TA018, TA031, and TA013.
The Serion features a varied topography that ranges from expansive ergs (sand seas) to towering sandstone formations and boulder fields. Its climate is categorized as BWh according to the Köppen classification system.