Plinius Line

The Plinius Line was a political border between US and Chinese territory on Earth's moon, Luna, prior to World War 3. The Plinius Line ran roughly East to West from the Plinius Crater along the Haemus Mountains and terminated North of the Manilus Crater. It followed along the natural boundary between Mare Tranquilitatis (Sea of Tranquility) and Mare Serenitatis (Sea of Serenity).
The Plinius Line was established at the beginning of the year 2100 after the US Secretary of Defense issued a warning over Chinese drones flying over Tranquility Base. Plinius Line was a line of demarcation over which any Chinese/SCO personnel, vehicles, or equipment crossing on the ground or at sub-orbital altitudes would be considered an act of war. The Chinese, in turn, declared that no US or other personnel from Tranquility Base would be allowed to cross to the North.
After the Lunar portion of World War 3, the Plinius Line was no longer relevant, however, the natural boundary along the Haemus Mountains has since been used as a border between nations and other entities within the Seas of Tranquility and Serenity.

Type

Region

Location under

Luna