Sometimes, when you go astral, you'll find yourself in locations that just feel like they mean Serious Business. Here, the entities are serious and businesslike, and can be quite helpful. So, people who return from there call them astral temples.
Does one create it? It feels more like attuning to something like that which is already there. Just sit with the concept of whatever you want to focus on, and the standards of discipline surrounding that idea. The creation part of it can be more like this: http://duskenpath.tumblr.com/post/57391809915/astral-creation-magix-by-dusken Except bigger.