Morrigu Barrow Wall

"Do you sense something? Behind that wall?"

- Sakaki

Morrigu Barrow Wall (モーリー・バロウ城砦, Mōrī Barou-jōsai, lit. "Morley Barrow Fortress") is a field located at Δ Hidden Forbidden Bulwark. It is one of the Lost Grounds.

The World R:2 Official Story
Morrigu Barrow is a great gate blocking passage to heaven. It is protected by the god of judgment, Folset. The One Sin was supposedly used here in an attempt to break the wall.

.hack//G.U.+
After receiving a message from Sakaki, Atoli travels here by herself. After waiting awhile for Sakaki to appear, she is surprised when Azure Kite suddenly warps into the area.

.hack//G.U. Games
Morrigu Barrow Wall is first seen when Yata and Ovan meet there. Ovan asks Yata what he thinks lies beyond the great wall, and Yata responds that nothing does—the area beyond the wall is simply a blind spot to the players where nothing exists. Ovan rebuts that he senses something on the other side, and that the wall is part of a prison. Yata rhetorically questions whether it is the presence on the other side that is being trapped, or if it is the players of The World themselves.

At one point, Piros the 3rd catches word that a new "Tri-Edge" mark has appeared here. He summons Haseo to help him stake out the area, in hopes that Tri-Edge, the culprit who ruined his wall graphic, will return to the scene of the crime. However, after discovering that Piros the 3rd intends to wait for Tri-Edge indefinitely, Haseo gives up and returns to Mac Anu. When he returns later, he finds that Piros is still in the area, having fallen asleep at his computer. While attempting to wake him up, Haseo notices Sakaki and Atoli entering the area. Eavesdropping on their conversation, he realizes that Atoli had been spying on him for Sakaki.

Later, while seeking out the "Tri-Edge" that Haseo is after, Atoli's power leads her to this Lost Ground. She activates the mark on the wall and is transported to a strange area, completely blank except for a stack of coin lockers, that exists outside of the system. Haseo, Kuhn, and Pi are sent by Yata to investigate her disappearance from the bounds of the system, and follow her to the strange area, where they encounter Azure Kite.

Much later, following Corbenik's "Rebirth", Yata invites Haseo here so he can show him a strange anomaly. This anomaly turns out to be Cubia, which begins to flood "The World" with a swarm of Gomora. During the fight against Cubia, Haseo returns here to enter an Outer Dungeon. He is assisted by several Captains from Moon Tree who fend off the Gomora while Haseo opens up the portal to the dungeon.

.hack//G.U. Novels
Morrigu Barrow Wall was a Lost Ground discovered by the Twilight Brigade. From atop the Six Ringing Peaks of Al Fadel, Kuhn sees The World completely encircled by the Wall, with nothing beyond it.

Dark Morrigu Barrow Wall
Dark Morrigu Barrow Wall (裏モーリー・バロウ城砦, Ura Mōrī Barou-jōsai, lit. "Reversed Morley Barrow Fortress") is located at Θ Returning Invincible Huge Being. The One Sin and God Eater appear here.

Trivia

 * "Morrigu" is the original Irish spelling of the name Morgana, and refers to the Celtic goddess (or trio of goddess - Morrigu, Babd and Macha) of death, battle, and in some cases, life/rebirth. It may also be a reference to Morganna, the former goddess of The World.
 * A barrow is a type of burial mound, where a body is placed inside of a mound of earth, a popular practice in ancient Ireland. In this case the wall is guarding the graves of the Gods, who were destroyed by the Human's Crest Gun.
 * Dark Morrigu Barrow Wall is the only Chaos-Gate-accessible Lost Ground that does not have an Area Keyword beginning with "Hidden Forbidden".