The Cavern Realm was the 3rd realm the humans entered. It is located inside of a huge cave, with stalactites and stalagmites as hazards and obstacles. The track often parts into many different tracks, but then merges back into one track. There are bat-like creatures that dwell inside this realm.
- Karma Eiss - Chicane
- Kurt Wylde - Battle Spec
- Shirako Takamoto - Bassline
- Tork Maddox - Hollowback
- Deezel "Porkchop" Riggs - Jack Hammer
- Mark Wylde - Spine Buster
- This is the only realm won by the humans between movies.
- This is the first and only realm won by a Metal Maniac.
- This realm marks the first time Shirako is the main focus of a racing realm.
- This is the first realm which only six drivers are sent in.