Oteron Valley lies between the Petrovan Mountains and the Brandashire Escarpment, and the corresponding nations of Petrova and Oter, respectively. Originally, the Valley was a part of Oter, but the discovery of nephelium near the Petrova border spurred a dispute between the neighbours. After generations of warring, the nations signed the Treaty of Oestara, thereby ending the conflict. Today, the newly founded nation of Oestara fills the Valley.
Politically, the region is more properly referred to as Oestara in an effort to establish that nations sovereignty over the area. Geographically, and to all nations uninvolved in the nephelium conflict, it can still be called Oteron Valley. Oter will likewise use the geographical name for the area.