Chasm Cave is a dungeon in Pokemon Mystery Dungeon Explorers of Time & Darkness, and Sky. It is the first dungeon in the future. Since it's in the future, it can't be revisited and no Pokémon can be recruited.
Chasm Cave is a special dungeon because there are no walls. If you walk off the path, you'll be teleported elsewhere. Enemies can also attack you from the empty spaces.
Pecha Scarf, Power Band, Stamina Band, Special Band, Defense Scarf, Heal Ribbon, Joy Ribbon, Insomniscope, Scope Lens, Persim Band, Twist Band, Zinc Band