Lyg

"Lyg is in the future, inverted from distortion of time. It's so far East that it's West, coffee stained into obscurity." – mojonation1487

Lyg is one of the most well-known of the mysterious Adjacent Places (also known as the Places-Not-Quite-There) that exist on Mundus, and has existed as long as Tamriel has existed, for the two are intricately tied together similar to the way Lorkhan and Akatosh are tied together: one needs the other in order to survive.

Currently, mojonation1487 (Chris Franzen in real life) is the extraordinary man behind Lyg, and has been given exclusive rights by Michael Kirkbride to build up this mysterious but extremely interesting continent that so few truly understand.

The Nature of Lyg
As stated above, Lyg is one of the Adjacent Places. The Adjacent places are not like the Planes of Oblivion or Aetherius, as they are not defined to exactly exist; the Adjacent Places can't be exactly pinpointed or discovered, but there is an exact place where they are. They're confusing realms to say the least, and no one knows truly how many exist. However, we do now know for a fact that Lyg is one of them and has existed in previous kalpas and currently exists in this one as well.

Lyg is described as 'mirror' of Tamriel, and that is exactly what it is. RottenDeadite, a user from /r/teslore, described Lyg in a perfect way:

"Now let's talk about Lyg.

''If Lyg is the "Future" of Tamriel, it's not relevant to the denizens of Tamriel. Not in any way. Because it exists in the future, it has no impact on the Present.''

''When people call Lyg the "coffee stain" of Tamriel, it's because it's a replica of Tamriel that's "leaked" through the paper and formed a mirror-image on the other side. The metaphor is not casually chosen. Just consider the "paper" to be the same as the paper used to inscribe an Elder Scroll. The words on the paper are creatia. The letters are numbers. The language is mathematics.''

''Lyg is an "echo" of Tamriel. The fact that it appears inverted is just a Fata Morgana mirage caused by the perception of an object through the thermal inversion of extreme time dilation. But because it lives beyond the event horizon of current time, Tamriel will never have to worry about what insanity such a place might breed. That would be impossible.''

''Except, what if it was possible? A good writer never lets something like impossibility get in the way of a good story."''

In simpler terms, Lyg exists as a futuristic Tamriel where everything is backwards than mainstream Tamriel. Different gods our worshiped, the races bear different names and histories, and the technology is more advanced than the steampunk tech that the Dwemer were fond of creating. However, Lyg still goes through the same events that Tamriel has gone through in the past (like the events of the games); they just happen in a very different way. And of course, happened in the past.

While it is possible for transportation between Tamriel and Lyg to occur, it is incredibly rare and extremely unlikely to happen. Even worse, it is dangerous on a large scale. A event known as a Bleed is what happens when the two become linked for the shortest time, and is when Lyg tries to 'eat' Tamriel. The last time this occurred was in the Third Era.

Mentions of Lyg
Mankar Camoran, the leader of the Mythic Dawn, wrote about Lyg in fourth volume of the Mythic Dawn Commentaries, and it is probably one of the most knowledgeable pieces about Lyg:

"I give my soul to the Magna Ge, sayeth the joyous in Paradise, for they created Mehrunes the Razor in secret, in the very bowels of Lyg, the domain of the Upstart who vanishes. Though they came from diverse waters, each Get shared sole purpose: to artifice a prince of good, spinning his likeness in random swath, and imbuing him with Oblivion's most precious and scarce asset: hope."

"Deny not that these days shall come again, my novitiates! For as Mehrunes threw down Lyg and cracked his face, declaring each of the nineteen and nine and nine oceans Free, so shall he crack the serpent crown of the Cyrodiils and make federation!"

"Suns were riven as your red legions moved from Lyg to the hinterlands of chill, a legion for each Get, and Kuri was thrown down and Djaf was thrown down and Horma-Gile was crushed with coldsalt and forevermore called Hor and so shall it be again under the time of Gates."

Lyg is where the Daedric Prince Mehrunes Dagon was 'forged' by the divine beings known as the Magne Ge. Dagon also 'threw down Lyg and cracked his face', which shows that he destroyed it. We also learn the names of places that exist in Lyg: Kuri, Djaf, and Horma-Gile (which is and will forever be called simply Hor now). Whether Lyg still exists in a operational state is unknown, but we know that it was either destroyed in a previous kalpa or in the current one because of this information.

The book Exegesis of Merid-Nunda also mentions Lyg, but only briefly:

"… were known as the Nine Coruscations, who followed the parabolas that led away from Magnus. Merid-Nunda was of these Sisters, as was Mnemo-Li, as was Xero-Lyg, as was …."

One of the Magne-Ge bears Lyg in her name, which makes sense as the Ge are worshiped on the continent of Lyg.

Djaf: Arena of Lyg
mojonation1487 has released an extraordinary work on one of the cities of Lyg, known as Djaf, before its fall. Provides a good insight on the politics and cultures of Lyg, as well as explores interesting concepts about it as well.

On The Origin of the Name Lyg
Written by Michael Kirkbride, this short but greatly useful story explains the 'creation myth' around the name Lyg, and how it was discovered by the Tamrielics.