The Forbidden Layer occupies SL1500, between the Feast Layer and the Planet Core. Its route crosses concrete towers, shifting materials and open chasms. Your most useful tool here is a thrown chunk of terrain: inside a Securitone’s throw zone, it creates a trail of Passage Stone that you can follow.
The collection list contains 25 entries. The opening reward is a bunch of five, so completing the list adds 29 Banandium Gems to your total. There are also 30 frog fossils. Leave the Grumpy Kong reward for your return after defeating King K. Rool in New Donk City.
Route through SL1500
Take the opening gem bunch, then inspect the shaft before moving outside. Shuffle Stones change their material on a timer. Wait for a climbable or breakable surface instead of trying to force your way through the wrong phase.
Activate the checkpoints at the First, Second and Third Concrete Towers. Pay the Securitones to create throw zones, then aim terrain toward your next safe landing. Keep gold available: progressing through the layer requires more than 12,000 gold in payments. Finish nearby challenges before leaving each tower so that you do not have to rebuild the same paths repeatedly.
At Go-No-Further Gate, check both sides of the checkpoint and the high wall. This area contains the final challenges, the Smashintone reward and the chip exchange. Continue beyond the gate when you are ready to face Void Kong.
All 25 Collection Entries
| Entry | Where to look or what to do |
|---|---|
| 1 | Collect the five-gem bunch where you land. |
| 2 | Climb above the shaft’s alternating ceiling during its breakable phase. |
| 3 | First challenge: reach the large platform after the opening path. |
| 4 | First challenge: explore the extra sideways wall route. |
| 5 | First challenge: inspect the approach to the Barrel Cannon. |
| 6 | First tower’s battle portal: defeat four Illuminoids with overhead shadows. |
| 7 | Inspect the large island between the first two towers. |
| 8 | Near entry 7, descend through the changing square; follow the ceiling course. |
| 9 | Enter the second tower from underneath; break the changing block inside. |
| 10 | Second tower’s battle portal: defeat three Buzzoids. |
| 11 | Build a route to the isolated island beside the third tower. |
| 12 | Check the rotating triangular platforms beyond the third tower. |
| 13 | Talk to Cranky on the high island above the third tower’s throw zone. |
| 14 | Second challenge: collect the gem before boarding the mine cart. |
| 15 | Second challenge: burst all five mine-cart balloons. |
| 16 | Second challenge: finish the course. |
| 17 | Collect the gem as you reach Go-No-Further Gate. |
| 18 | Pay 600 gold for the gate’s battle challenge; defeat three Crockoids. |
| 19 | Destroy 30,000 m³ of Passage Stone, then visit Smashintone at the gate. |
| 20 | Descend right of the gate and make a path through the lava. |
| 21 | Pay 1,000 gold for Ostrich Bananza: Free Climbing; scale its first section. |
| 22 | Third challenge: inspect the snow wall in the second section. |
| 23 | Third challenge: reach the top of the final tower. |
| 24 | After the New Donk City rematch, visit Grumpy beyond King K. Rool’s Escape. |
| 25 | Buy the gem at the Go-No-Further chip exchange. |
Boss Battle: Void Kong
This fight removes your Bananza transformations. Use regular DK movement, terrain throws and close-range punches. Clear the opening Crockoids, throw sand toward Void Kong and follow the stone trail upward. Keep adding sections when the next platform is out of reach.
Watch his rockets while crossing a narrow path. Their trails can help you move, but a hit can break your route. After reaching Void Kong, punch him until he relocates. Rebuild your approach to the next platform and time your jump over the energy barrier before closing in.
On the larger sandy island, focus on the Terravoiders that support his shield. Avoid the enemies and move away from the red markings that warn of falling pillars. Once the shield generators are destroyed, use Turf Surf to cross the lava, evade the remaining attacks and reach Void Kong for the final punches.
Before Continuing to the Planet Core
Compare your collection list with the entries above. Revisit unfinished challenge portals before tackling a broad search of the overworld. For fossils, search remaining terrain systematically and use fossil maps to narrow down missing locations. A first story visit will still leave the postgame Grumpy Kong reward outstanding.