- "The Gerudo Desert once held a prison built to hold the worst criminals this land has ever known... The criminals who were sentenced to death were sent directly to the underworld by a cursed mirror that was kept in the prison... Now that prison is condemned, and even the road leading to the desert is impassable. This desert at world's end... It still holds the cursed mirror and the malice of the doomed inmates..."
- — Auru
Located in the Gerudo Desert, the Arbiter's Grounds served as a prison where convicts were either executed or banished to the Underworld through the use of the Mirror of Twilight. It was also the site of Ganondorf's death sentence by the Ancient Sages. Ganondorf survived his execution, however, but was stopped and banished to the Twilight Realm, where he gave Zant his kingship and powers of sorcery.
After Link retrieves the Master Sword, Midna directs him to the Arbiter's Grounds so that they can enter the Twilight Realm using the Mirror of Twilight found within. Upon reaching the top room of the Arbiter's Grounds, Midna and Link stumble across a massive skeletal beast. Zant appears and plunges a magic blade into its skull, reanimating it as Stallord. After the battle, Link and Midna enter the Mirror Chamber, only to find the Mirror of Twilight broken. The Ancient Sages appear and explain to them the tale of Ganondorf's execution and that Zant fragmented the mirror.
The Arbiter's Grounds are located in Gerudo Desert, which is only accessible from via the Oasis Flight in Lake Hylia before Twilight Portals are opened. The dungeon is desert themed; it is filled with quicksand and sand whirlpools. Along the way, Link must face many undead monsters, related to the backstory of a prison. The dungeon features many dark areas and puzzles which require the use of the Lantern, as well as Poison Mites which can be scared away by the lantern. In this dungeon, Link frequently needs his wolf form to advance. To complete the dungeon, Link must defeat a Poe, learn its scent, and use it to track down three more Poe. The mini-boss, Death Sword, must be fought in wolf form during part of the battle. After Death Sword is defeated, Link will no longer need his wolf form, as the rest of the dungeon is focused on the new item, the Spinner. The boss is a fossil, reanimated by Zant, known as Stallord. At the top of the dungeon is the Mirror of Twilight. This is the only dungeon where Midna does not create a portal in the boss room to leave, as it is possible to warp freely to and from the area at the end of the dungeon.
The Arbiter's Grounds appears in the North-Eastern portion of Gerudo Desert. It has two Keeps (the Arbiter's Keep and Sacred Grounds). In the Ganondorf's Return story scenario, the Arbiter's Grounds is under the control of the Monster Forces, though later falls under the control of Ganondorf's Forces after King Dodongo, Gohma, and Manhandla are defeated by Ganondorf. In the Enduring Resolve story scenario, Ghirahim and Zant hide out and observe the Ganondorf's Forces battle with the Hyrulean Forces from the safety of Sacred Grounds, while their doubles (Fake Ghirahim and Fake Zant) fight in their place, though the Hyrulean Forces eventually realize the deception. They are eventually discovered in the Sacred Grounds by the Hyrulean Forces and defeated. It is one of the few dungeons from past The Legend of Zelda titles to appear as a part of a stage in Hyrule Warriors.
The Arbiter's Grounds returns as part of the Gerudo Desert stage. In addition to the original daytime version of the Gerudo Desert stage from Hyrule Warriors, there is also a nighttime version which also features the Arbiter's Grounds.
The Arbiter's Grounds are often believed to be the Spirit Temple from Ocarina of Time. Both are found near Gerudo Desert and share architectural similarities (for example, a statue of the Goddess of the Sand seems to appear both at the top of the Arbiter's Grounds as well as within the Grounds themselves and is also a prominent feature of the Spirit Temple). Furthermore, mirrors were prominent in the Spirit Temple, and the Mirror of Twilight bears resemblance to the large round mirror that Link used to access the Spirit Temple's boss chamber. It should be noted, however, that there was no colosseum-type dome at the top of the Spirit Temple, so it may be pure Hylian addition. The fact that the Arbiter's Grounds housed many paranormal demons and spirits also seems to further support the idea that the Grounds were once the Spirit Temple, the place of worship for the spirits of Hyrule, particularly the Goddess of the Sand.
Another possibility is that the section of desert that Arbiter's Ground was located in another part of Haunted Wasteland that was inaccessible to the Hero of Time due to the sandstorms that raged there (it should be noted that the Hero of Time only managed to access the Desert Colossus region due to the assist of the Phantom Guide and Requiem of Spirit, indicating it is highly plausible that the Arbiter's Grounds could have existed in another part of the Haunted Wasteland which could have eventually became the Desert Province seen in Twilight Princess). The architectural similarities between the two also simply be due to them having been built by the either the Sages and/or Gerudo inhabiting the desert. It is also possible that the Arbiter's Grounds was originally a Temple were the Mirror of Twilight was stored and guarded by the Ancient Sages during the evens of Ocarina of Time, explaining their absence in that game, and was later converted into a prison at some point after Ganondorf's betrayal was exposed by the Hero of Time, leading to his capture and attempted execution.
The Arbiter's Grounds is also similar to the Shadow Temple and Bottom of the Well from Ocarina of Time as they are both prison-like structures that contain undead monsters and spirits. One possibility is the Shadow Temple and Bottom of the Well originally served as part of the prison system of Hyrule containing criminals, traitors, and other enemies of the kingdom, which was operated by the Sheikah. After the Sheikah's overall decline, a new prison the Arbiter's Ground was eventually constructed in Gerudo Desert, taking advantage of the foreboding desert to reduce the risk of escape, possibly as a direct result of Ganondorf's capture (as Ganondorf was the leader of the Gerudo that originally ruled over Gerudo Desert) and imprisonment.
Arbiter is another word for judge. While the name of the place seems to refer to one judge, during the execution of Ganondorf, more than one Sage is present. It might be a central area for arbitration, to a point where it was considered a being. Alternatively, the word arbiters may refer to the Ancient Sages who passed judgments within the Arbiter's Grounds.