Location from Pikmin 2 by Nintendo / Shigeru Miyamoto
The third and deepest cave of the Valley of Repose — eight sublevels with the Empress Bulblax at the bottom, guarding two of the Exploration Kit upgrades.
The Frontier Cavern is notable for containing two Exploration Kit upgrades: the Rocket Fist (a stronger punch attack) from the Brute Knuckles, and the Rush Boots (faster running) from the Repugnant Appendage — both guarded by the Empress Bulblax. Getting to her requires clearing eight sublevels of enemies that prefer projectile attacks. The cave is also the only one in the game with two Exploration Kit items, making it unusually valuable for progression. The Empress Bulblax here births Bulborb Larva continuously — the fight is as much about managing the swarms as it is about attacking the boss.
A cave that shifts from snow-cold to something warmer as it descends. Eight sublevels of escalating enemy density. The final sublevel is the Empress Bulblax's domain — wide open, designed for a creature that attacks by rolling.
Also known as: Frontier Cavern