Redstone Warren in the TV series
Redstone was a warren in the TV series of Watership Down, where Primrose used to live until an Efrafan Wide Patrol came and took her away. Sometime between Primrose's imprisonment in Efrafa and her freedom on Watership Down, Redstone Warren fell to a mysterious sickness, leaving Captain Broom as its only survivor. It is implied that the spirits of the Warren stayed in the burrows of the warren because Primrose needed them, and they were soon set free when Primrose lets go of the past and leaves with Hazel and Captain Broom to her new life on the Down.
Later, Hickory, Marigold, and several others rabbits discovered Redstone Warren after escaping from the Warren of the Shining Wires, and lived there peacefully, until the warren attracted many elil, including Man. Sometime afterwards, the Warren was destroyed by Man, and the Redstone rabbits now live on Watership Down.