Netherworld

"When people fall under a sleeping curse, the soul travels to a Netherworld, where it resides until awoken. Now, this world is between life and death, and it’s very real. However, even when the curse is broken, sometimes, in sleep, the victims find their way back to that world. Victims like you."

- Mr. Gold to Henry Mills The Netherworld is a location featured on ABC's Once Upon a Time. It first appears in the seventh episode of the second season.

History
Aurora and Henry dream of a red room with no doors and no windows, with red curtains burning all around the room. ("Tallahassee")

Henry meets again with Aurora in the Red Room. Some time later, he returns with a magic necklace around his neck that gives him control over the journey so that he cannot be hurt by the flames, and tells her his name. ("Child of the Moon")

Henry tries to tell Aurora that in order to defeat Cora, Emma Swan and Mary Margaret Blanchard need the squid ink from Rumplestiltskin's cell. Some time later, David Nolan is put under the Sleeping Curse in order to communicate with Mary Margaret, but he appears in a black room surrounded by mirrors. He discovers that the red room is under the one he is in, so he breaks the floor and falls to where Mary Margaret is. He tells her what Henry tried to tell Aurora, but when they try to break his curse by true love's kiss, they realize that they are not able to touch physically. ("Into the Deep")

Ways to Travel to the Netherworld

 * Being under the Sleeping Curse. ("Into the Deep")
 * By falling asleep after the curse is broken.  ("Child of the Moon")
 * By falling into a deeper sleep than normal after the "side effects" of the Sleeping Curse are banished.  ("Into the Deep")

Prominent Locations

 * Hall of Mirrors: When someone is put under a Sleeping Curse, their soul is transported to a room filled with mirrors until they awake. It is located above the Red Room.
 * Red Room: Once someone has awoken from the Sleeping Curse, when they sleep again they may find themselves in a red room with no windows or doors engulfed in flames.

Trivia

 * Mr. Gold says this netherworld is between life and death.
 * Cora hinted that Prince Phillip's soul was taken to a world in darkness. ("Into the Deep")