The geological structure on the planetary surface known as the Escarpment, a high mountain range with some peaks rising above the atmosphere, lifted from the sunrise side, it encircles the globe of Ephesus III at an angle which runs nearly the diameter of the planet, on a diagonal. The slot canyons that bisect the Escarpment were identified as being regularly spaced along its length. The reasoning behind the mathematical relationship of the slot canyons, though known (1-3-5-7), has not been matched to any other surface features.
Two hundred and forty-three slot canyons bisect the range, scattered around the planet. Each canyon is from fifteen to one hundred and twelve miles long. As the planet rotates, there is a tremendous air pressure build-up on the sunward side due to atmospheric heating. The Escarpment regulates the flow of air from one side of the planet to the other. Tremendous winds howl down the slot canyons as the edge of the pressure dome hits the edge of the Escarpment.
Several caves hold First Sun traps.