Desert Colossus

The Desert Colossus is the name of a vast, secluded desert in Ocarina of Time. It is situated at the rear of the Haunted Wasteland, far out of Hyrule's boundaries. It can only be accessed by those who possess the "eye of truth". In order to enter the massive desert, Link must first venture through the two trials of the Haunted Wasteland. The first trial is the River of Sand, meaning Link must either use the Hover Boots or the Longshot to safely get across the river of quicksand. After crossing the river, the young hero must then follow several flags to reach a stone structure that leads to the the second trial: the Phantom Guide. Using the Lens of Truth while on top of the monument reveals a Poe that will guide Link into the Desert Colossus itself.

The Desert Colossus is home to an oasis located at the west portion of the area. At first, the oasis is dried up, but it gets filled up after playing the Song of Storms on a small, rock platform near it. Fairies will also sprout up from the now-filled oasis, serving as a Fairy's Fountain of sorts where Link can return and get healed at any time.

On the opposite side of the oasis is a Great Fairy's Fountain; however, its entrance is blocked off by a cracked wall. Link can open it up by simply bombing it up, finding a Great Fairy inside that will bestow upon him the Nayru's Love spell.

Goddess of the Sand
The most prominent feature of the desert is a a giant monument known both as the Desert Colossus and the Goddess of the Sand. Located inside the Goddess of the Sand is the Spirit Temple, which serves as the headquarters of Nabooru, the leader of the Gerudo and second-in-command to Ganondorf, in order to conduct experiments in brainwashing people.

The enormous statue is a vast carving in the stone believed to be made by the Gerudo to represent their Goddess of the Sand. Before Ganondorf gained entrance to the Sacred Realm and took the Triforce of Power, this ancient stronghold was the secret hideout for him and his followers. During his seven year reign as ruler of Hyrule, the ancient building became the base of operations for his surrogate mothers, collectively known as Twinrova.

When Link first enters the Spirit Temple located inside the Goddess of the Sand itself, he finds that he cannot go in further than the first chamber since both the west and east entrances are impassable. Sheik appears before him as the young hero exits the temple and teaches him the Requiem of Spirit, the melody necessary to access the Desert Colossus as a child and successfully enter the first half of the Spirit Temple.

Trivia

 * In Twilight Princess, the room that houses the Mirror of Twilight contains a statue that is very similar to the Desert Colossus.