Asgard

Asgard is introduced in The Avengers: Earth's Mightiest Heroes episode, " The Siege of Asgard".

Origin
Asgard, even though inhabited, is physically different from Earth and other planets. Asgard is not a sphere-like shape, but a piece of land that floats in space. Asgard also doesn't rotate on an axis nor does it rotate around the sun, though there may be an object of some sort that gives it its sunlight. Gravity is similarly like Earth, although heavier. For example, a chair made of wood would be considerably heavier than one on Earth. What keeps the land together is unknown, but it keeps it together. Water doesn't pour from the land, as the gravity keeps it there as well.

Asgard itself is connected to nine other dimensions which form the nine worlds of Asgardian cosmology through naturally occurring dimensional portals. Sometimes the nine different worlds have been treated as the same dimension with Midgard (Earth) being separate.

Creation
Asgard's true origin is unknown due to the cycle of Ragnaroks. According to one story, originally there was a void, Ginnungagap, bounded on either side by fire Muspelheim, the land of fire and Niflheim, the land of ice. When fire and ice met, they combined to form a giant named Ymir and a cow named Audhumbla who nourished Ymir. She survived by licking the salty ice blocks. From her licking emerged Buri who fathered Bor and through him the Asgardian race. Bor took the frost giant Bestia as his wife and fathered three children: Odin, Vili, and Ve. Bor is attributed with founding the city of Asgard and being its first king. The three brothers eventually slew Ymir and from his body made the Earth and humanity. After Bor's disappearance and the deaths of his brothers in battle with Surtur Odin became the sole ruler of the gods.

Another version states Asgard as it exist now only came into being about two thousand years ago. Every few thousand years Asgard is destroyed in Ragnarok only for a new Odin to form, rebuild the city and start the cycle anew with the gods living similar lives as they did before with slight differences. This cycle was perpetuated by mysterious beings called Those Who Sit Above in Shadow so they could feed off the energy released before being broken by Thor.

Another version given recently by Odin states when Odin and his brothers were children Bor took a seed from a dimensional rift and planted it in the ground creating the World Tree. It is unknown if this merely connected the nine worlds, created all of them including Asgard, or some combination.

Another version suggest the beings who became known as the Norse gods were formed from the "godstuff" scattered by Atum the God-Eater after he slew the evil elder gods. This godstuff was shaped by early human perceptions which formed all modern pantheons. The gods then eventually travelled from Earth to the dimension that became known as Asgard.

Another version suggest the gods were originally tribes of mortals that somehow ascended to godhood and eventually moved to Asgard.

It is unknown to what extent any of these stories are true. It is possible several of them are true or bits and pieces from various ones from the true origin. It is also possible none of them are true.

Whatever the original beginnings, Odin's desire to lead Asgard led him to betray his father during a battle with frost giants. With Bor turned to snow then scattered by the winds and his brothers fallen in battle with Surtur, Odin became the High Father of Asgard. As the years passed, Odin's wisdom grew stronger and he sought to understand more of the universe beyond the nine worlds. His curiosity lead to war with the Dark Gods, a pantheon of alien gods that were Asgard's opposite in ever way that mattered. War broke out between them and Asgard fell for the first time. After Thor aided his father in battle, Odin retook Asgard and banished the Dark Gods. Centuries passed and Asgard fell victim to Sutur of Muspelhiem, and in a final battle, Odin and Sutur were killed in battle and Asgard fell once again. However, they both returned alive and Odin return to rule the kingdom.

Odin learned of the cycle of Ragnarok and kept it secret from his people. At one point, the Egyptian god, Seth sought to destroy Asgard and with Thor lost in Onslaught, he saw it as the perfect time to claim Asgard and end the cycle to reshape the kingdom to his rule. However, the Asgardians rose and stopped Seth but in their weaken state, the Dark Gods returned and destroyed Asgard to reshape in their own image. Eventually, Thor returned and freed his people and Asgard returned to its wondrous state again. However, those times grew dark again as Surtur returned to Earth and Odin was once again lost and Thor took over as ruler. Thor moved Asgard to Earth and attempted to better life for all humans, but due to Resistance from without and treachery from within eventually subjugated the Earth to his rule. In time, he was force to face his crimes and returning to the past prevented that timeline from ever coming about. His actions during this caused the Odinforce to leave him making Asgard vulnerable. In was during this time that Loki started Ragnarok and sought to reshape Asgard in his own way. He devastated Asgard until Thor had discovered the truth and used the powers of the Rune Stones to end Loki's rule and break the endless cycle of Those who Sit above in Shadow for good.

Attractions

 * Dome of Combat
 * Giant Bust of Odin
 * Hall of Heroes
 * Monument to the Unknown Warrior
 * Museum of Weaponry
 * Shopping Center
 * Temple of Titans
 * Warlock's Haven
 * Warrior's Walk
 * Yggasdral (Tree of Life) Monument

The Nine Worlds
There are Nine Worlds in the Asgardian cosmology. Over the years they have been treated both as separate dimensions and as one dimension.
 * Asgard which is the home of the Asgardians.
 * Vanaheim which is the home of the Vanir.
 * Alfheim which is home to the Light Elves.
 * Midgard which is the Earthy plane of existence.
 * Jotunheim which is the home of the Giants.
 * Nidavellir which is home to the Dwarves.
 * Svartalfheim which is home to the Dark Elves.
 * Muspelheim which is home to the Demons
 * Hel which is the realm of the dead.