I hate being picky, but I guess that's just how I am. At least within anthropology, when we are talking about knowledge about the origin of the universe, we use the term cosmogony. The structure or geography of the universe falls under the term cosmography. They both are subfields of cosmology, which covers knowledge about the universe in general. So a creation myth would be referred to as part of a culture's cosmogony. An idea of how the universe is constructed, such as the three-tiered universe in Asian and Native American shamanism would fall under the heading of cosmography.