Cult of Luna is a swedish post-metal/sludge/doom band. So far they've released seven albums more or less of which some has grown to become classics in the post-metal scene. They're up there with the bands such as Isis and Neurosis.
My favorite albums is probably the first S/T "Cult of Luna", "Somewhere along the Highway" and "Eternal Kingdom".
"Eternal Kingdom" has an very intresting story behind it's making. When the band was rehearsing in a old mental institution they found a diary from a former inmate called "Holger Nilsson" who had written these stories about a kingdom in the north, controlled by evil creatures blaming them for ther murder of his wife. Ahh, I won't tell you anymore about this story you can listen to the album
Oh, Cult of Luna has also produced a book out of this story actually. Haven't read it myself yet but I will in the near future