The ruin the Voss call the Dark Heart lies deep in the twisted Nightmare Lands. The few surviving texts on the Dark Heart describe the complex as a maze of chambers‒some sealed, others seemingly broken open from within‒and vast underground corridors. It is said to be a place of corrupted monsters and ancient secrets, and based on orbital reconnaissance scans may be the oldest structure on the planet.
The Sith Lord Nerrethel spent two years researching texts concerning the Dark Heart and formulated several theories. He claimed its architecture resembled that of the ancient Sith on Korriban, and made a detailed study of the Dark Heart's orientation relative to Voss's constellations. After attempting to visit the Dark Heart in person, however, Lord Nerrethel was found dead on the border of the Nightmare Lands. His notes from the expedition contained only the words “it sees.”