In my humble opinion the best album of Vangelis. The wikipedia article mentions it is a dark, moody and classical album. These are all things I appreciate in music, so it comes as no surprise to me. Vangelis also uses voice a lot here, in particular the English Chamber Choir. The main vocalist has also worked with Vangelis on Chariots of fire.
When I told my girlfriend at the time that I liked this record so much, she told me that if I liked this kind of music I should try the Carmina Burana of Carl Orff. I did, and indeed, I liked it.
I listened to this record endlessly while reading Tolkien’s Lord of the Rings. The images from that book that went through my head went into the music, and will never leave it for me.