I already understand this but I feel the answer is completely unsatisfactory and contradicts information already stated in the series (and the Director's Reports no less). The world's are separate by a great distance of space in all cases (even the Beach of Nothingness is stated to peer into the World of Darkness by Nomura, he never said you could reach it by being there.) and the World of Darkness presented in KH1 is locked away and yet here's Xemnas, with a Kingdom Hearts in his backyard as if it was always like this. Even if they were in "spitting distance" the worlds should be technically separate from each other by a barrier after the events of KH1. Its obvious that Xemnas didn't use a Corridor of Darkness to reach KH nor did DiZ when he tried to digitize KH. Kingdom Hearts is treated as physically existing in that world despite this contradicting the info given in KH1.
The worlds didn't create the DTD of KH1, the Seven Princess's of Heart created the means to reach it with the Final Keyhole. KH1 pretty much implies that the DTD is at a specific location just as it also implies Kingdom Hearts (or at least the Heart of Worlds) is located in a specific place (World of Darkness) how then can KH and the DTD be ethereal and intangible things that come and go on a whim as KHII implies?After Sora defeats Xemnas in the dream-Memory Skyscraper, Xemnas absorbs the power of KH. Meaning KH is actually inside him, because he absorbed it. (SPOILER)He "became one with KH," like he said in the Secret Reports of 358/2 Days. The door that SDG travel through leads to KH, which happens to be inside Xemnas, because as Mickey said, the Worlds created that door. The Worlds created the door to KH in KH1 and they do it again in KH2, even though KH was temporarily relocated.
Basically are there two Kingdom Hearts as Nomura implies in his interview? Is the Heart of Worlds located in the Realm of Darkness and is the Heart of Man an abstract concept that exist wherever it wishes to be? If both are one part of the true Kingdom Hearts, how then can Xemnas and Heartless Xehanort truly achive their goals by only obtaining what appears to be one half of the cosmological whole? Or is KH something like a physics and philosophical allusion to the Christian concept of the Trinity? Being both tangible and intangible, being a place both physically and metaphorically.
This is ultimately what I'm trying to discover and regretfully, Nomura's interview only makes the issue more difficult to comprehend.