"This is less about the world being created specifically, and more a section of the cosmos. Midgard categorizes it in their myths as a great World Tree, Yggdrasil. Nine realms, that is planets, sit in the branches of this galaxy. Asgard is near the top, just below Muspelheim, with Vanaheim almost on the same level. Just below that lies Jotunheim. Midgard is near the middle, as are Alfheim and slightly below that, Svartalfheim. Nidavellir is in this region too, and at the bottom lies Niflheim." If need be, he'd make an illusion of it for Puck but hopefully this explanation would suffice.

"The Jotun, along with the Svartalfhar--that is, the dark elves--are actually some of the most ancestral enemies to the Asgardians. They've tried to conquer the other realms before, including notably on Midgard about 1000 years ago. They were repelled by Midgardians, but mostly with Odin and the army of Asgard's aid."