The entrance to Ghost King's Crevice simply didn't exist.
Many had attempted to reshape the land for convenience in the years this sub-universe had existed, but none of their solutions managed to remain present as time passed.
Because the Impulse Wave was a truly destructive event. It tore the world apart and rebuilt it from scratch, remodeling the scenery in its natural form without the manmade changes that influenced it.
The strangest thing was…the Impulse Wave killed everything in the realm until the very edge of Ghost King's Crevice. Unless one was deep underground or in the safe area before the crevice, death was inevitable and instant.
Nevertheless, because of this unpredictable phenomenon, attempts to terraform the land ceased thousands of years ago.
The only way to enter the crevice was to descend its steep wall.