Earth Temple

The Earth Temple is one of the two main temples and the fifth dungeon to be explored in The Wind Waker, located leagues beneath the Great Sea down in the now-sunken land of Hyrule, beneath Headstone Island. After the triumph of the Hero of Time over the Dark Beast Ganon at the end of Ocarina of Time and his subsequent journey back to his own age, it was decided that two new temples (the Earth Temple and the Wind Temple) would be constructed to safeguard the power to repel evil that dwells within the enchanted blade the Master Sword, by means of providing a place for the two new Sages to offer up their prayers to the Golden Goddesses, the prayer song for the Sage of Earth being the Earth God's Lyric. When the Dark Lord Ganondorf somehow escaped from his exile in the tainted Sacred Realm, he returned to Hyrule in a red wrath and found that there was no Hero present to oppose him, causing him to seek a way to deacvtivate the Master Sword. In turn, he ordered the great Poe, Jalhalla, to invade the Earth Temple and murder the then-sitting Sage of Earth, the Zora known as Laruto. After Laruto’s death and the following invasion of Hyrule orchestrated by the Dark Lord, the Golden Goddesses brought down a torrential downpour known as the Great Flood that buried the land of Hyrule beneath a vast ocean that came to be known in time as the Great Sea. The entire kingdom and all still in it (namely Ganondorf and his army) were sealed within an enchanted air chamber that prevented the water from destroying the kingdom, and the entire kingdom was left frozen in time. The water did not leak into the Earth Temple, as its two entrances were safely out of the water's reach. It was here that Laruto’s spirit lingered on, awaiting the time when a new Hero armed with the Master Sword would come with a successor Sage to restore its power and destroy the evil that now haunted the temple. Many centuries later, Link, the Hero of Winds, came to investigate what became of the Sages of the Master Sword and to restore the Master Sword’s power to repel evil. He brought with him Laruto’s predestined successor, a Rito by the name of Medli, who bore the harp once used by Laruto herself, and they worked together to solve the mysteries of the Earth Temple and to purge it of evil. They faced many evil creatures within the temple (defeating a set of Stalfos along the way) and destroyed Jalhalla, freeing Laruto of her obligations and partially restoring the Master Sword’s former power.

Construction
After the sealing away of the Dark Beast Ganon within the corrupted Sacred Realm by the legendary Hero of Time and the Hero’s journey through the flows of time back to his own age at the end of Ocarina of Time, it was decided that two new temples for two new Sages, the Sages of the Master Sword, would be constructed in order to safeguard the power to repel evil that dwells within the enchanted blade of the Hero’s weapon, the Master Sword, so that it would always be ready to be used should Ganondorf ever return from his exile in the corrupted Sacred Realm. One of these two temples was the Earth Temple, a structure built to honor the spirits of the earth and that would provide a place for the Sage of Earth to offer up his or her prayers to the Golden Goddesses for the Master Sword to forever retain its power within the Sage shrine deep at the heart of the temple.

The Earth Temple was built within one of the tall mountains to Hyrule’s southern borders (similar to its counterpart, the Wind Temple, to Hyrule’s northern borders), and two entrances to the temple were created for it: one at the ground level and one at the summit of the mountain. The temple was built largely with gray blocks of stone and was decorated with many statues depicting the sun and the moon fused together, perhaps to demonstrate the duality of light and shadow or day and night. A magical harp was constructed for the Sage of Earth that would be the tool for carrying the Sage’s prayers to the goddesses, and the harp would pass down the line of Sages in succession. The deepest chamber of the temple was a large, open chamber with a mosaic of the Triforce adorning its tiled floor and many windows in the roof to allow light to flow into it. It was here that the Sage of Earth would go to play the Earth God's Lyric to carry his or her prayers to the goddesses for the Blade of Evil’s Bane, and the Sage would typically be conducted by the sitting ruler of Hyrule, who would wield the magical conductor’s baton known as the Wind Waker. As long as a sitting Sage was placed in each temple, offering up their prayers to the goddesses, the Master Sword continued to be blessed with its magical power to repel evil, and so it was for a time following the Hero of Time’s disappearance into the currents of time.

The Return of Ganon and the Great Flood
Many long years passed by for the land of Hyrule and its people, and the land knew a peace and prosperity that allowed it to flourish thanks to the efforts of the Seven Sages and the Hero of Time. However, it was not meant to last, for the great evil that had been defeated by the Hero was on the move once again. The Dark Lord Ganondorf somehow discovered a way to break the Seal of the Seven Sages and returned to Hyrule in a red wrath, intending to make good on his final threat to the Seven Sages and the Hero of Time that he would make their descendants pay for his imprisonment. Ganondorf soon realized that the Hero of Time was not present to oppose him, nor apparently were his descendants (having been sent back to his own age, the Hero of Time and his descendants were no longer present in this branch of Hyrule’s history). Upon this realization, the Dark Lord sought a way to deactivate the only real threat left to him: the Master Sword. He soon discovered the existence of the Sages of the Master Sword and came to the realization that to achieve this goal, he needed simply to dispose of them in order to render the blade useless against him. To this end, he ordered one of his loyal monsters, the great Poe known as Jalhalla, to invade the Earth Temple and murder the Sage of Earth. The great King of Poes did as instructed, laying siege to the Earth Temple and attacking the sitting Sage of Earth, a Zora by the name of Laruto. Jalhalla killed Laruto and took over the latter’s shrine chamber, rendering the Master Sword powerless against the Dark Lord in conjunction with Molgera, a great sandworm whom Ganondorf had ordered to simultaneously invade the Wind Temple and kill the Wind Sage as well.

After he was quite sure that the Master Sword could no longer pose a threat to him, Ganondorf assumed his bestial form of the Dark Beast Ganon and attacked the kingdom of Hyrule head on with his evil army, leaving a trail of death and destruction in his wake. Hyrule’s people prayed for the legendary Hero of Time to once again come to save them from Ganon, but due to his journey back to his own time, he nor his descendants could answer the cries of the people in this branch of Hyrule’s history. Left with no Hero to take up the Master Sword against Ganon, King Daphnes Nohansen Hyrule and his people prayed to the Golden Goddesses for deliverance from destruction at the hands of Ganon, and when their prayers reached the goddess’ ears, their prayers were finally answered. The goddesses instructed Hyrule’s people to take refuge on the mountaintops and brought down a torrential downpour that came to be known in time as the Great Flood, a deluge that soon buried the fair land of Hyrule and all still in it at the time (namely Ganondorf and his army) beneath a vast ocean that came to be known as the Great Sea. They also sealed Hyrule within an enchanted air chamber that prevented the waters of the Great Sea from leaking in and destroying Hyrule completely as well as casting a spell over the land that left it frozen in time. The Earth Temple (along with the Wind Temple) was left intact as the water was unable to leak into it due to its two entrances being safely out of the water’s reach, one on the mountaintop now above the waves and the other down in Hyrule itself. It was here that Laruto’s spirit lingered on, awaiting the day when a new Hero would come with a successor Sage to destroy the evil that now haunted the Earth Temple and return the power to repel evil to the enchanted blade of the Master Sword.

Trivia

 * The reason Zoras were sages of the Earth Temple was probably due to its close proximity to Lake Hylia.
 * The Earth and Wind Temples cover the elements not already represented by the temples in Ocarina of Time, though they are more analogous to "shadow-" and "spirit-themed" levels in comparison.