Mairne has a single large ocean, the only standing body of water on the entire planet, lined with deserts which in turn blend into glacial tundra. Rifts in the planetary crust extend all the way down into the core, creating significant volcanic activity that frequently changes the shoreline and makes the ever-changing landscape of Mairne difficult to map out. Several impact craters, souvenirs from space battles taking place in orbit around Mairne, pock its surface.