The Deep Caverns aka the Dark Caverns are dark and dangerous caverns located beneath SlugTerra, and is where the purified evil known as Dark Water can be found, as well as sinister creatures known as the Darkbane and their monsters currently reside, who intend to conquer the worlds above. It is as well home of The Goon, Dr. Blakk, & Tad (as well as his slug Pieper) thanks to the Shane Gang.
- Deadweed (Mentioned only)
- The New Kid Part 2 (Mentioned only)
- What Lies Beneath (First appearance)
- Back to Blakk (Appears in flashback(s))
- Dark as Night (Mentioned only)
- Light as Day
- The Fall of the Eastern Champion (Appears in flashback(s))
- The Emperor Strikes Back (Mentioned only)
- The Return of the Eastern Champion (Mentioned only)
- Slugterra: Into the Shadows (Cameo)
- The Deep Caverns are located 18-19 levels of earth below SlugTerra as stated by Junjie.
- Tempestos and the Air Elemental (ghouled) are the only known slugs (ghouls) capiable of creating portals to the Deep Caverns.
- It has been seen that entering the Deep Caverns through an unstable portal can cause drastic body changes, as seen with Dr. Blakk who his skin turned pale.
- With enough ghouled slugs, the Guardian Gates that divide SlugTerra and the Deep Caverns can be weakened & broken.
- Or with enough ghouls, terraportals large enough for entire armies to pass through can also be created.
- Will Shane, Dr. Blakk, The Goon, The Emperor, & Tad (and Pieper) are all currently in the Deep Caverns.