The border that sets apart the confines of Las Noches apart from the rest of Hueco Mundo, a wall inclined slightly outwards, at such lengths that it covers the entire area of Las Noches seamlessly without exit or entrance, and at such heights that traversing it upwards would potentially take hours. Its surface is made of stone, while its inner layer is made of tempered steel, making it quite durable and resistant to even the most powerful of attacks. As an added bonus, there are several spires dispersed evenly throughout the wall that send out a peculiar pulse wave of sorts. These waves prevent trans-dimensional travel to Las Noches, but not from it. It is also built with a failsafe, wherein destruction of even a part of its structure would trigger an explosive charge found within its innermost core which would set off an explosion, loud and bright enough to be seen and heard throughout Las Noches. And though the explosion isn’t as damaging as one would think, it is proficient in its task of acting as the first line of both defense and warning, in case one would seek to invade Las Noches.
This is the outermost part of Las Noches, any and all outsiders must pass through this first before entering. Before venturing into the other parts of Las Noches, one must post here first, if one is an outsider. The post must include a description of how the RPC traversed the massive wall.