|Appears in (video game)|
The Forbidden Ruins is a temple located in the Valley of the Kings. The ruins are a location used for a pact made by a dark clan. The pact involved sealing DarkNite within the ruins, capable of being Summoned by a member of the pact, possessing all seven of the Millennium Items.
The ruins contains statues of pharaohs and Millennium Items. Inside a hidden chamber is DarkNite's resting place. A large tablet, with spaces for each Millennium Item is inside this chamber. The ruins also contain drawings on the walls seeming to depict ancient duel monster battles. One of the drawings seems to vaguely resemble Doma, The Angel of Silence. There is also ancient text carved on the walls as well.
Atem gathered six of the seven Millennium Items and with Seto betraying Heishin, he got all seven. Seto brought him back to the ruins, to destroy them, but revealed his true agenda, to use the Items to fulfill the pact himself, as he shows Atem a hidden chamber. Atem and Seto duel over who should take the Items. Atem wins, but Heishin appears and holds a knife to Seto's neck. Claiming to be aware that Seto had planned to betray him, he let him continue, as Seto was a descendant of the dark clan, required to complete the pact. Atem was forced to hand over the Items.
Using the Items, Heishin performed the ritual to summon DarkNite. Without the Millennium Items, Heishin had no proof he had complete the pact. DarkNite refused to allow Heishin to command him and turned Heishin into a card and burned it.
Using the Millennium Item Cards, Atem held DarkNite back and dueled to put DarkNite to rest. Atem won, but DarkNite transformed into Nitemare and forced another Duel. Atem defeats Nitemare sealing away his evil.
Afterwards, Atem ordered the ruins to be buried.