• Tartarus—Mentioned only once in the New Testament in 2 Peter 2:4, Tartarus is the prison house for fallen angels (demons) who sinned heinously in Genesis 6:1–4 by cohabiting with women. In Greek mythology, Tartarus was the lowest chamber of the underworld. The demons locked there will remain in custody until the day of their final judgment (see 2 Peter 2:4).