Frosty Depths

The Frosty Depths is the first cave you'll find in Pikmin: Connection of the Worlds and is found at the Rugged Tundra. It serves as the tutorial cave for the game, as it has only 3 floors, 6 treasures, and easy enemies (only rivaled with the Peaceful Well, one of two caves in the Garden). The Bronze Key, required for unlocking the Garden and the Great Volcano, is found here.

Accessing the Frosty Depths
There's a cardboard box in front of an icy river that cuts through the land. It blocks a bridge that goes to an island in the river, and two more split off. Since you can only grow a maximum of 25 Pikmin the first day, you'll have to come back to grow more Pikmin. 40 or more can crush this box. Afterward, build the two bridges (there's really a third one; it's blocked by some ice) and continue forward. The snow-covered grass gets taller and taller, so watch out for some enemies that might surprise you! It gets so tall that it fills the camera, but then suddenly disappears. The hole is in view!

Sublevel 1
Your first level, it starts out simple: similar to that of the Emergence Cave from Pikmin 2. There are two small chambers joined together, and there are three Snow Bulborbs guarding a treasure. If you collect the enemy carcasses back to the Research Pod, it will say how it loathes collecting those "disgusting, decaying bodies" (also a reference to Pikmin 2) but is willing to collect them, which trades them for Pokos. Get the treasure and leave.

Sublevel 2
Now there are more Snow Bulborbs here. At least ten are scattered randomly around the level, which is made of two chambers again, but a series of passageways connect them. Both of the treasures are in alcoves, but some Snow Bulborbs may or may not be guarding them. There are also a couple of eggs here, which might contain Mitites. Find the hole, then go down it...

Sublevel 3
This level is quite big. A single tunnel leads down to a chamber with 10 Dwarf Red Bulborbs, a treasure, and two eggs. The Bulborbs are guarding the treasure, so kill them and get them out of the way. After this chamber, a short passageway leads to another chamber. The final chamber houses the escape geyser, however, with a Red Bulborb and 10 more Dwarf Red Bulborbs. A treasure is being protected by some Dwarf Bulborbs, and the Red Bulborb is holding the Bronze Key. Defeat the Red Bulborb and retrieve the Bronze Key.

Wildlife

 * Snow Bulborb × 13
 * Dwarf Red Bulborb × 20
 * Red Bulborb × 1
 * Mitite × ?