The Underground appears in a few episodes of BFDI, and it is usually accessed by digging downward or a heavy impact towards the ground.
In "Return of the Rocket Ship", X goes underground to try to find his treasure. The challenge is to go underground and try to find the treasure before him.
In "The Four is Lava", Bleh is trapped underground because of the magma. Lollipop tells Saw to swim through the magma get to Four to rescue them, but Saw refused because she does not want to lose her new pink handle. Dora protects saws handle using her mouth, and they both make it to the surface. After Dora notifies Four about the rest of their team being trapped underground by magma, Four is happy to help them, and rescues Bleh from the magma.
|Locations in Battle for BFB (Category)|
|500-step platform • Bathrooms • BRB • Buried Forest, Deciduously Insulated • Cake at Stake Place • Cliffside • Data Void • Earth • Elsewhere on Earth • Eternal Algebra Class Withfour • Gelatin's Steakhouse • Goiky • Golf Ball's Underground Factory • Space • Swimming Pool • Team Rooms • The Desert • The Fourest • The Moon • The Other Continent • Underground • Waterfall • World's Largest Oven|