Yggdrasil, and of some of the Nine Worlds that are in the Tree.
Sometimes, it seems as if all literature and fiction is one long series where everything connects. Thus, the Marvel Comics Thor sends a doomsday device to Nastrond and Wikipedia informs us that Nastrond is a place in Hel which is the ninth world.
In speech balloon 1, panel 5, of the attached comic book page, Thor refers to "...the wastes of Nastrond."
-Mark Millar, The Ultimates, Vol 2, Homeland Security (New York, 2004), Chapter Thirteen, "How I Learned To Love The Hulk."
Regular blog readers might remember that, late at night, I switch from prose fiction to graphic fiction for a change of pace but then find something relevant in the graphic fiction.
This is a modernized, hippified Thor very unlike the oafish, boorish original (see combox here).