The Reverse Side of the World (世界の裏側, Sekai no Uragawa?) is the layer of the World that retains the laws of the Age of Gods, housing Phantasmal Species instead of people. The world where humans currently live employing the laws of physics is like a fabric that thinly extends across the surface of the planet, and underneath this fabric exists the Reverse Side of the World, where supernatural beings have retreated to after the Age of Gods ended. Finally, beneath that fabric exists the planet known as "Earth". In other words, the Earth is the bottom layer of the planet, and it is covered by the “Reverse Side of the World” — the place where the laws of the "World" as it once was reigns, and covering that is the "Present World" where humans of the Age of Man live.
Rhongomyniad is one of the "anchors" that fasten the planet together to ensure that the world of humans on the outermost layer of the world can't be destroyed by those on the Reverse Side who wish to reenact the Age of Gods. The Holy Spear that King Arthur holds is nothing more than a shadow of the main body: a tower that fastens together the skin of the world. It exists to be the planet's anchor and to ensure the World's stability.
In Fate/Apocrypha, Sieg in his Fafnir dragon form migrates the Greater Grail to the Reverse Side of the World. In the Reverse Side of the World, the Holy Grail cannot activate Amakusa Shirou Tokisada's wish of "Salvation of mankind through the Third Magic" simply because no humans exist there. Reaching the Reverse Side of the World as a Heroic Spirit is not impossible because Heroic Spirits have already become inhuman the moment they died; however, the probability is incredibly close to zero. In order to reach the Reverse Side to reunite with Sieg, Jeanne d’Arc essentially tried an infinite number of times from the Throne of Heroes, which was removed from the time axis. Manaka Sajyou encounters Sieg when she sends her consciousness through the "Reverse Side of the World" in Fate/Labyrinth.
Avalon (アヴァロン, Avaron?) is the paradise in the Arthurian legends, existing in the Reverse Side of the World at the same coordinates as Britain. It is a small world that was called the Land of the Eternal Spring and the Island of Apples in mythology, the utopia was thought to be derived from the island that produced the "Apple of Immortality" in Greek mythology. King Arthur and Francis Drake are said to dwell in Avalon, the city of the dead, and will eventually return to lead England to true glory.
It is a Utopia that may not be granted to beasts which possess wisdom, one that may never be reached. It is a world cut off from the constant decay and destruction of the surface of the planet and, although it is nestled in human history, has no connection to other lands at all. Daytime is filled with spring’s sunshine and the smell of summer; night is wrapped in the autumn air and stars of winter. It is where flowers of all colours bloom on gently sloping plains. A forest can be clearly seen in the far distance, enveloped by the overlooking sky; the view is evenly divided between the sky and the earth. There is no sign of human civilization in the lands. On earth there are countless flowers and bugs; in the forest there is water and green, and ethereally beautiful fairies lurk in the pond. The paradise people imagine is only an imitation of this place. Here, in this un-trodden place, the bounds of a tabooed land (禁足地, kinsoku-chi?) serve as the ends of the island. Though the island has no end, it seems to change like any other land. Further into the island the land turns barren, similar to Britain. It is where fairies got up and went to after the Age of Gods ended.
According to Merlin, the density of magical energy in Avalon is too strong. He thought it should not be called a paradise, but it could be better utilized as a weapon instead. He compares the place to a vacuum, simply breathing in it is enough to end up dead. In one breath a human of the current age would burst from inside out.
Once Artoria Pendragon terminated her contract with the World by destroying the Holy Grail by her own will, she goes to Avalon. In the Last Episode, Shirou Emiya was able to reach Avalon and reunite with Artoria.
- ↑ 1.0 1.1
 Fate/Apocrypha material - Encyclopedia: Other Side of the World [Others], p.173 [T]
- ↑ Garden of Avalon - Chapter 02: The light of the stars, p.040-052
- ↑ Fate/Grand Order - Altria Pendragon (Alter - Lancer), Translation by Master of Chaos
 Fate/side material - Encyclopedia: The Everdistant Utopia [Noble Phantasm], p.063 [T]
 Fate/Extra - Rider Matrix [T]
Master: Shinji Matou
True Name: Francis Drake
Noble Phantasm: Hunt of the Golden Hind: Golden Stag and the Eventide Tempest
Keyword: Invincible Armada, Logbook
Strength: D, Defense: C, Agility: B, Magic: E, Luck: EX
Anti-Magic: D, Rider on the Storm: A+, Settler of the Stars: EX
Kewords Skills Details