Gaia Temple

The Gaia Temples (ガイア神殿), also known as the Temples of Gaia, are structures that appears in Sonic Unleashed. They are a set of seven ancient temples that are located around the world. By grasping the very power of the planet itself and with the aid of the Chaos Emeralds, these temples have the ability to bring the world back together when it is broken into pieces by Dark Gaia following the Time of Awakening, and as well restore the Chaos Emeralds should they lose their power. If all seven Chaos Emeralds are brought to their respective temples, then the world will be whole again. They have a strong connection to Light Gaia.

Description
The Gaia Temples are immensely large temples in various shapes. Their function is to harness the very power of the planet itself and work in sync with the Chaos Emeralds, with the purpose of repairing the world back together whenever it is broken into several pieces by the awakening of Dark Gaia and seal up Dark Gaia itself. Their ability to harness the planet's power also act as a mean of restoring the Chaos Emeralds' power in the case they have been drained of them.

The process of restoring the planet and sealing Dark Gaia is through placing the seven Chaos Emeralds in a small altar found in the center of the temple. The emeralds' power will then provide the energy needed for the Gaia Temples to help the Earth heal naturally from Dark Gaia's awakening. In the case the emeralds have been drained of their power, placing them in the alter will cause the emeralds to be recharged through the planet's power. In turn the act of the emeralds being recharged leads to the equal and opposite reaction of the emeralds healing the Earth.

Since Light Gaia has been the one performing the process of restoring the planet since the beginning of time, it is unknown for what purpose the Gaia Temples were created, though they were most created to aid Light Gaia in his mission to stop Dark Gaia and bring the world back to normal, and as well to act as extensions of Light Gaia himself.

Chip shares a special connection with the temples, due to the fact that they share the job of restoring the planet's condition. With Chip's innate Light Gaia powers he can activate the altar and reveal the hole for the Chaos Emerald to be placed and can also sense the location of the temples after realizing his identity. It is within Adabat's Gaia Temple that his memory is restored by finding an apparent fragment of his essence inside it. As seen during the battle against Dark Gaia, Chip is able to call the Gaia Temples to his location in times of self-defense in order to form the body of the Gaia Colossus.

History
According to the Gaia Manuscripts, the Gaia Temples were created "ages ago" by an unknown civilization at different points across the globe.

In Sonic Unleashed, Dr. Eggman learned about the Gaia Temples from the Gaia Manuscripts. After somewhat successfully awakening Dark Gaia with his Chaos Energy Cannon and splitting the Earth apart, the doctor sought to secure the Gaia Temples as they could prove to be a threat to his plans. Meanwhile, Sonic the Hedgehog and Chip (aka. Light Gaia) began to seek out the Gaia Temples in order to restore the planet and stop Dark Gaia's resurrection.

Not long afterward, Dr. Eggman learned that Sonic was still alive from their last encounter, and as such deployed his forces to the Gaia Temples to slow down Sonic while completing his plans with Dark Gaia's energies. These efforts proved to be in vain, as Sonic and Chip were successful in reaching all seven temples, stopping the doctor's plans and putting the world back together.

In the process of the restoration of the final continent, the Gaia Temples were all called together by Chip to form the Gaia Colossus in the insuring battle with Dark Gaia, and later Perfect Dark Gaia. All of the Gaia Temples were laater presumably destroyed when Chip and the Gaia Colossus were resealed inside the Earth's core following the defeat of Perfect Dark Gaia.

Locations

 * Mazuri: Guarded by Dr. Eggman's Egg Beetle.
 * Chun-nan: Guarded by the Dark Gaia Phoenix.
 * Spagonia: Guarded by Dr. Eggman's Egg Devil Ray.
 * Holoska: Guarded by Dark Moray.
 * Shamar: Guarded by the Dark Guardian.
 * Adabat: Guarded by Dr. Eggman's Egg Lancer.
 * Eggmanland: Unguarded, although the player does fight Dr. Eggman's Egg Dragoon after restoring this temple.

Temple Guardians
As shown on the PS2/Wii version of Sonic Unleashed, each Gaia Temple (except the one in Eggmanland) has one or more appointed human guardians, named "Temple Guardians",  who watches over the Gaia Temples and deem whether a person are worthy to use the Gaia Gates that lead to the temples. These people are the latest in a long line of guardians who have watched over the temples since ancient times. These people are also the only ones who can assemble a Planet Tablet. The following known guardians are:
 * Gwek - guardian of Mazuri's Gaia Temple.
 * Zonshen and the Dark Gaia Phoenix - guardians of Chun-nan's Gaia Temple.
 * Otto and Lucia - guardians of Spagonia's Gaia Temple.
 * Sarianna and Jari-Thure - guardians of Holoska's Gaia Temple
 * Ehsan - guardian of Shamar's Gaia Temple.
 * Teanchai - guardian of Adabat's Gaia Temple

Trivia

 * While it is unknown what kind of civilization that created the Gaia Temples, this civilization is the oldest confirmed civilization presented in the Sonic the Hedgehog series so far; the Black Arms are said to have visited Earth for about 2000 years, and the Knuckles Clan and the Nocturnus Clan are confirmed to go as far back as 4000 years, while the civilization that created the Gaia Temples goes as far back as at least tens of thousands of years.
 * Each temple has the Chaos Emerald on the Earth's continent to restore a powerless one: Green - Mazuri, Red - Chun Nan, Blue - Spagonia, Cyan - Holoska, Yellow - Shamar, Purple - Adabat and Silver - Eggmanland.
 * Apotos and Empire City are the only areas without Gaia Temples.