I'm thinking one of two possibilities, 1 the trope of this type of manhwa where the place doesn't exist in this plane of reality but superimposes on it to open a path, usually either because of natural cycles of dimensional drift or the owner's intent if said owner is above a certain level and able to directly interfere with sub-space or 2 he's exactly where he's looking for...but needs to look down... (like the library from Avatar season 2)