In the 13th, the barrier between the material plane and the Feywild is thinner than anywhere else in the City, allowing many fey to cross into the City, as well as for many strange, otherworldly parts of the City that seem to exist only in the Feywild to manifest. As a result of this, the district is home to many magic shops and curio markets, of both fey coming to trade, and residents trying to sell the things they picked up while on the other side.
The district is split roughly in half by the river, with the north bank being generally associated with the seelie fey, and the south bank being associated with the unseelie.
The people who live in the district are highly superstitious, with each having their own beliefs about how to avoid accidently crossing. These vary from taking off their hats as you cross a bridge, to whispering prayers as you walk, to avoiding certain streets at certain times, to keeping a handful of dirt from your home with you. Some wards seem to work better than others, but generally residents agree that travelling alone at night, especially crossing the bridges or taking an unfamiliar route, invites bad luck.
The main thing that attracts tourists to this district is the Wanderer's Market, a weekly event where residents of the district try to sell the things they've found or bought while in the Feywild. People come from across the City to see what unique trinkets they can take home, knowing that most items brought back are one-of-a-kind, and might even bear some hidden magic in them. Those fey with a use for gold also often participate, bringing homemade trinkets and curios to amaze and sometimes (lightly) curse their buyers.
However, some people entering this market, particularly in the morning, instead find themselves in The Market of Beautiful Things. In this beautiful glade among the cobblestones, Fey bring goods (often magical, always otherworldly), to trade for worldly beautiful things. Visitors come, and if they like what is on offer at a stall, they offer a gift to the fey, and if it is appreciated, they will recieve something in kind. The gifts the fey will accept vary greatly between the vendors, some love fine, handcrafted goods, others want rare things, like shining gemstones from deep in the earth, while some seek natural beauty - a delicate flower or a colourful poisonous frog. A person who crosses here to trade must be careful however, as offending one of the vendors by offering a gift considered ugly or unsuited to their tastes often means receiving a curse in exchange (it is rude not to accept the gift, so the fey must, even if it is distasteful to them; in return, they give you something you'll find equally distasteful, and you can't help but accept).
On the Unseelie side, the most famous location to cross into is the Twilight Market, where magical boons of all natures can be bought and recieved, all for a much more personal cost. The unseelie fey here deal in pacts and sacrifices, trading boons for favours in kind, curses, or the loss of certain memories or magic.
Blackthorne Street is a fey part of the City that's accessed very rarely, usually only by the will of one of its occupants. On the Unseelie side of town, wanderers at twilight will sometimes find themselves on a street of mostly abandoned shops and houses, with all but a few boarded up and falling apart. The few places that are open seem almost uncanny next to the ruins surroudning them; bright, magically illuminated signs begging guests to enter.
The first is a icy cold inn, ran by a Winter Eladrin who revels in cold nights of little rest. With a silent glare, those who enter are led to barren, freezing cold inn rooms, the doors closing behind them with a sheer wind, windows frozen over with ice. Upon sleeping in the inn's beds, guests have the most terrible nightmares of their past, and wake up feeling restless, as if they've barely slept. The inn's owner refuses to speak or answer questions, putting a finger to her lips and shushing any attempts to talk. After their first night, guests are free to leave, though many struggle to leave their beds due to the cold and exhaustion, and remain trapped there for her to draw more nights of misery out of. Those with the willpower to leave can wake up others, but with great protests from the host, as she wields the cold to force them out.
Across from there is a small shop with dark windows, only lit by what little light can enter from the purple sky above. Inside, a shady figure, difficult to make out in the darkness, sells powerful potions and poisons, all for an unspecified debt, to be repayed after the potions are used. The figure never explains the debt further, and those who question it are just met with a hollow, echoing laugh from behind the counter.
Finally, the last notable structure is a collapsed house. Once proud and tall, this place strange building is now nothing but rubble. It was once home to a coven of hags: one green, one sea, and one night hag, who would draw people in need to Blackthorne Street, and offer them a deal. While at first their boons did grant power, the gift would drain the bearer, letting the hags slowly corrupt and consume them. in the Winter of 148T, 3 people cursed by the hags destroyed the impossible tower, and took revenge for what was done to them. "Claws", a thief who had had their hands taken and replaced with crab claws after stealing from the sea hag; Boarholder, previously a researcher from Aberrations Incorporated who wouldn't stop attempting to study the green hag, and so was turned into a beholder-like being and fused with his pet boar; and Avarice, a parasitic sword created as a curse for another, coming back to claim to life of its creator after 200 years, using the body of Agony. Since the house was destroyed it has remained in ruin, and Blackthorne Street has lost much of the power it once held.
As a part of destroying the Blackthorne Street coven, Agony and Boarholder both inadvertently created ooze clones of themselves, Agoony and Gooholder. These two helped defeat the hags, and afterwards opened up an unnamed curio shop on the South Bank, where they collect the fey oddities that interest them, trading them to customers with more interesting trinkets. Recently, they had a tiny mimic child delivered to them by CH103 Cogwright, as part of her initiation into the Messenger's Order.