From Bulbapedia, the community-driven Pokémon encyclopedia.
Frigid Cavern (Japanese: こおりのどうくつ Ice Cave) is a Friend Area. It is the only area in the Glacier area, and has a capacity of seven Pokémon. It can be bought from Wigglytuff of Pokémon Square for 9,000 Poké.
It is a freezing cold cavern filled with ice and snow. In the center is a platform with a large snowflake design. In the back is a place that looks like a cave or shrine of some sort.
A cavern where ice shattered by wind makes huge drifts. There are Pokémon that thrive in this bitterly cold place.