The Forbidden Jungles was a location on the planet Nok that was the homeworld of the Indigo Tribe. Centuries ago, the native inhabitants of the planet lived within these jungles where they were captured by alien slavers that imprisoned them for transportation off-planet. This ended when Abin Sur helped free the natives with the aid of Natromo who showed the Green Lantern the Indigo Light of Compassion that formed in a wellspring in the jungles of the planet. Together, they managed to defeat the invaders whereupon the people of Nok returned to the Forbidden Jungles. However, Natromo helped forge an Indigo Lantern Power Ring for Abin Sur in order to create the Indigo Tribe who were formed from some of the worst criminals in the universe.