Can't say enough about the work being done with Wardruna. A combination of textural ambient with field recordings of nature, tribal rhythms, chanting (as well as singing), and Nordic folk/spiritualism based on the Elder Futhark Runes. The lead vocalist is Ghaal, formerly of Gorgoroth but don't let that make your mind up about what kind of sound you are about to hear.
Here is one of my favorites from Runaljod - Yggdrasil.
And the entire album.