Original: Sanctuary Fortress
From Metroid Prime 2
Theme of Sanctuary Fortress
Composed by Kenji Yamamoto
Light Arrangement

Sanctuary Fortress is my favorite location in all of Metroid, and it has one of my favorite themes to boot. You're constantly expecting ruins and abandoned alien civilizations, only to be greeted with an entire city still standing from a long finished war, no visible damage save that all of its inhabitants are missing. Metroid Prime 2 had some of the most interesting and expanded lore in the entire series, considering it didn't feature the Chozo.