StarClan

StarClan is the place where good, virtuous Clan cats go (kind of like Heaven).

Misty Paths
The entire prologue is set in StarClan. See Misty Paths/Cliffnotes.

Descended from the Night
StarClan isn't mentioned once yet in Descended from the Night, as Shadow Dancer, the main character, has not joined a Clan yet. Weaselpaw probably believes in StarClan, however.

List of Known StarClan Places

 * Warmrocks
 * The Forest of the River
 * Silverpelt (or, the Milky Way)
 * The Brackenplace
 * Sweet Rowans

List of Known StarClan Cats

 * Starlingwing
 * Icecrow
 * Jaymask
 * Daisyflight
 * Wingpaw
 * Acornclaw
 * Breezewhisper
 * Dusklion
 * Plovershore
 * Leafstripe
 * Flowerstar
 * Jumpfoot
 * Mossfire
 * Shimmerpaw
 * Hickorynose
 * Deadfoot