It takes about three weeks to move through Shadow to Yig using Pattern; hellriders can make the distance in three days if they don't get delayed by riding into some disaster. Yig roughly marks the boundary point at which the power of Amber fades and that of Chaos waxes. It is also believed to hold up the heavens in some manner or sense. Yig once seemed different every time one visited it; this has changed.
Yig is a tree with a trunk a good half mile across that rises so high into the sky you cannot see its top. Tunnels sink into the earth around its roots, guarded by a serpent or worm (not the Serpent of Chaos, but possibly a relative), while a particularly vicious giant squirrel defends its upper reaches. Yig once stood in the center of a great, barren patch of earth; it has since become verdant and surrounded by lesser trees. It rains every afternoon.
Spreading in a circle around Yig proper is a tree village, the buildings woven of branches 400 feet above the ground, with a high shrub wall forming an outer barrier. The wall is broken at one point by the Great Pyramid of Time Passing, a ziggurat temple containing a massive calendar stone and observatory. Rivers spring from sources deep under the trees, and proceed outwards. An island in the center of the largest river houses the ornate ivory and sapphire pleasure dome of the Inner God Nymph. On one side of the river fields and steppe prairie stretch, the domains of Ram and Ox; Ox dwells by the river, Ram by the mountains. On the other side stretches thick jungle; Snake lives in a cobra-carved mahal by the river, and Tiger stalks the inland wilds. The outer limit of the realms is formed by a circle of high alpine mountains; on a peak thereof dwells Rooster, and a new Aerie for the Phoenix (basically a great fortress-temple) has been established there. A set of torii gates channels ley energy throughout, and here and there are sacred nodes of power.
Closer to the great tree is an artfully constructed courtyard. In the center is an elaborate fountain made of red stone, spouting a never-ending stream of living flames rather than any sort of liquid. To one side is a Sidar radio station with a broadcasting tower on top, constantly beaming music out and drawing the feelings of the remote listeners back in. To the other side, there is a grand sloped tlachi court, hewn from gray rock; two teams of spirit beings captained by Balance demons constantly play their game. The resurgent Sidar god Chac presides over the games on a pedestal near midcourt; he draws and gives power from the losers being sacrificed at one of two cenotes nearby (to be raised again the next day). Leading from these cenotes are graven channels that drain the blood and viscera of the victims toward a giant scrying bowl, presided over by a team of priests and magisters, constantly working their rites of far seeing, always replenished by the game nearby.
This new setup, from Yig at the center radiating outward through the tree village, the courtyards, the god-realms, and the surrounding defensive perimeter is referred to by some as Yig Complex.
From the branches once hung a giant man, a good hundred feet tall or more. Sometimes he was being hung by the neck. Sometimes a rope or spear pierced him, holding him in place. Sometimes he was crucified. Always his eyes are shut, he does not speak except to moan and babble about death and destruction, and his face mixes agony and pleasure (although mostly agony). Who he is or why he is there is unknown. Rumors said that when his tortures ended, he would learn the secret of life. Other rumors claim enlightenment comes to those who hang from this tree, while still others claim that it brings madness and suffering. Some say Fuyutsuki hung himself from it to learn how to make the Pattern. (Fuyutsuki himself claims he found the instructions in a book called Pattern Making For Dummies). Prince Shizumaru is known to have hung from Yig to gain the Seed of Hope, and it is said that Prince Drake hung from Yig to learn how to make Werewindle. It's said that Princess Kanna hung from Yig as well, prior to the Herald Crisis, and that Chloe of Rebma hung from it to unmask some sort of Abyssal conspiracy.
Yig's vulnerabilities are unclear, but Kanna has hunted down several Taylors who hoped to destroy Yig using weedkiller. The Black Heart Prophecy insinuates it could be destroyed using a Patternblade or a Logrusfoil.
Yig is defended by the Forestals, a group of potent druidical types who defend it from harm. They seem to be lead by a man named Forestal Troy. Akari has served as a Forestal in the past, and usually spends a few weeks each year at Yig since leaving active service. At least, they still count her as one of their own to this day.
The Logruswrack created a horrible strain on Yig, as the upset balance of the Logrus vs. Pattern shoved at the tree, making it lean badly. The Forestals struggled to keep it alive and well under the circumstances; apparently the Logrus jewel which was set in it (to balance the Wood Demijewel) was damaged or destroyed. Prince Shizumaru recently assisted in this by channeling some of the power of the Seed of Hope as well as elemental wood power from the Keep. Since then, Orien helped Anno install a new Logrus jewel to replace the broken one, and the newly recreated Two Trees helped rebalance it further.
Yig has recently been brought to full completion by the successful conclusion of the Grand Conjunction, the Sidar ritual that was used to empower it in the first place. The original Grand Conjunction was disrupted by several things, and Yig had endured in a semi-completed, hastily-patched state for centuries. Chloe, Jewel, Asuka, Fuyutsuki, and Anno finally finished the process, and now the Hanged Man (aka Professor Prospero) has been released from his torment to take his place as the avatar of Balance. And Chloe, Jewel, and Asuka seem to be the new parents of Yig. Whatever that means.
The Grand Dance of the Stars, with the recruitment of several new gods, seems to have further strengthened Yig, as has Chloe and Akari's expansion if Yig's ecosystem.
One of the items sought by High Master Namura of the Abyss is one of Yig's branches, which appears to be a crucial ingredient in his attempt to reforge Lian's spikard, to be used to escape the Abyss.
Yig in Arcadia is still a sapling, tended to by their group of Forestals which include ex-Wu Corrine and Juri.
Notable events at Yig in TAMD/UNS:
Notable events at Yig in the course of F9R: