To win the war against the Dead King, the Grand Alliance recognised that there would be a need for fresh sorceries, for unprecedented warding schemes and artefacts. Thus, a safe haven would have to be built for those scholars who would study the Dead King’s tricks and learn how to unmake them, too, one beyond his reach. And so the Arsenal was ordered raised.
The Arsenal itself is in neither the Twilight Ways, Arcadia or even Creation. Hierophant had, using Warlock’s old research and what he’d learned by stealing the ruins of Liesse, hung a fortress in a stable dimension somewhere between Twilight and Creation. The Witch of the Woods had then gone a step further and grafted on the Threshold, lesser dimensional pockets between the Arsenal and everything else.
The sheer amount of resources required to build the Arsenal meant that it was more feasible to lay false trails by the dozen and keep the location secret rather than attempt the improbable outcome of utter secrecy.
Notable Locations within the Arsenal
The Workshop concerns itself with the making of artefacts, armaments and alchemies. Its hallways are made of bare stone. A number of Named have their quarters in the workshop. Both Adanna of Smyrna, the Blessed Artificer's, and the Hunted Magician's quarters are located in the Workshop.  
At the Hunted Magician's request, a wine cellar was added. 
The Belfry’s mandate is broader in scope compared to the Workshop's. It involves the study of the Dead King’s creatures, war magic and warding, experimental research and the teaching of mages. The entire facility is carved out from the interior of single stolen Arcadian mountain, using existing caves that are now the Knot as the start. This accounts for strange, sprawling and yet stratified lay of the Arsenal.  The Belfry’s tallest heights reaches the summit of the mountain the Arsenal had been carved in.
The base of the Belfry is broadly square and made of stone. A long sculpted stalactite of what might once have been stone but is now a different material hangs from the top. The material has grown translucent from the sorcery poured into it, almost like a sort of crystal, and it offers a gentle glow. Fourteen floors of a great library sweeps upwards around the former stalactite. It is the single greatest repository of books in this Arsenal, and the lay of the stacks is also filled with writing desks and research nooks and even places to sleep. The stone railings on every floor parts to allow for a stone path leading into the crystalline hanging, which itself has been hollowed out and serves as both stairs upwards and way across. There is also a footbridge that ties the hanging spire of crystal to the sides of the Belfry.
There are lights and sights echoing within the translucent stone. The ‘windows’ at the highest ring of the Belfry are great silver scrying mirrors looking instead at the beautiful vistas of Arcadia and the Twilight Ways, at the seas and sky of Creation. There are smaller mirrors on lower levels showing such sights as well, all of them angled so that what they held within might echo in the central stalactite.
A few discreet hallways on different levels lead into personal quarters carved outwards from the Belfry, including Masego's located on the thirteenth floor.
The Belfry has a private eatery within and it is also where daily evening briefings are held. 
Masego's quarters are an amalgam of a workshop, library and bedchamber as conceived of by someone who sees little difference between the three.
Within Masego's quarters is a neat and well-organized library whose shelves went from floor to ceiling. A comfortable scribing desk with enough leg room for him to sit reading without feeling cramped was the only concession to this being somewhere actually lived in.
There is a larger room deeper in, a mixture of lazy chaos and almost rigid orderliness to be a nostalgic sight: Dirty clothes, plates with half-eaten meals on them and a blade cleaning kit Hakram had gifted Indrani a few years back had been strewn around without a care. In contrast, there is a a neat long table with half a dozen leather-bound manuscripts, stacked scrolls and carefully folded parchments, along with a nice leather armchair where Masego sits to work.
Another nook looks like a small alchemy lab, another like an enchanting table and yet another is covered in glass domes constraining pulsing luminous mushrooms.
There is a large bed in the corner, seemingly placed there almost like an afterthought – fitted in there after the important stuff had been, half-heartedly wedged in where there is still room. The dressers are on opposite sides of the room and the closet is awkwardly close to a cupboard opening the opposite way. The small table where meals are eaten – by the amount of dirty plates – is Archer’s work. There are a few hung tapestries on the walls along with a large amount of magelights and candles. Beautiful and elaborate carpets clearly from the Wasteland adds a splash of colour that livens up the room.
There is a small room behind all this, guarded behind a steel door warded tightly so none of the influences from the other parts of Masego's quarters can drift in and contaminate the workings. Here the walls are bare stone and even the tables and chairs polished granite, with only Masego's work on the Quartered Seasons breaking up the stony monotony. Half a dozen copper boxes with glass lids and water held in crystal spheres – an improvement on the traditional scrying bowl, though significantly more fragile – reveals shifting colourful shapes from places beyond Creation, while on the left wall a great slate covered in markings and formulas depicting the secrets that the Hierophant successfully teased out of the Pattern. 
The Depository is the part of the Arsenal where all the weapons and artefacts are kept in crates until they can be shipped to the fronts, and for storing all incoming supplies (including water, which is permanently rationed), functioning as a giant warehouse. Certain parts are more protected and restricted than others. Those least restricted are typically large rooms full of crates awaiting shipping out.
There are three protective chokepoints. In these areas, there are typically a few scholars in red, white or bronze – Gifted, priests, academics -, and mostly armed guards, handpicked from the different hosts of the Grand Alliance in equal numbers, and workers.
For the rooms that are less restricted, the key to the wards is a simple stone disk that unmade the sealing enchantment on the steel-barded door when pressed into a slot above the handle and remains within. There are other wards as well that act to prevent coming in by Arcadia and Twilight, and perhaps to prevent summoning within.
The Depository/Repository holds the Severance and the Autumn Crown.
Kept within the Repository and stored in a deep pool of ice cold water. The Severance is an artefact forged from the Saint of Sword's Aspect Sever, requiring eight Named to create it.
The pool is kept in a cube-shaped room of rock that has enchanted steel doors as well as bare walls with pulsing runes carved into it. There is a walkway out, with holy water surrounding the area. The walkway has been specially designed to rise and lower without relying on sorcery.  The cube also has wards that protect it from attacks.
The Spins is a soft-sloped spiral leading into eight different broad hallways of different heights, functioning so that several of the warehouses in the Depostiory are layered atop each other, so that they could all be accessed by wagon. Most of the hallways lead to warehouses, though the ‘central’ hall heads deeper into the Repository, where the restricted sections and the war assets are kept.
Accomodations meant to host important guests, essentially acting as the Arsenal's diplomatic quarters. Taking up an entire wing of the Arsenal, there are luxurious private quarters, private dining rooms, and the kind of parlour where a prince or a queen could receive important guests away from prying ears.  The rooms are connected to quite a few other sections by private halls not meant to be used by anyone else.
One of the parlours is is not large in size, fitted with two sofas and a low table taking up the greater part of the room and service tables and tapestries taking up the rest.
There are three private dining rooms in the Alcazar. One of the dining rooms is a formal banquet hall, while the other two are smaller rooms. One of the smaller room has walls covered by panels of painted wood that donated by the Princess of Cantal. 
There are attendants available for help for those staying in the Alcaza.
A quiet place where only a few are allowed entry, the Chancel is the smallest section of the Arsenal. Its wards are designed by Masego.
Within its walls, the Chancel holds several matters of variable importance. In order of their level:
- The central warding array
- The Mirage
- The restricted stacks
- The offices of the Arsenal treasury
Central warding array
The central warding array is protected by three checkpoints and has emergency wards in case the main array goes down.
The Mirage is heavily restricted. Guards who are heavily armed and armoured are not allowed beyond the first checkpoint. The second gate opens only for a drop of the proper blood, fresh from the body, and will fill the hallway with hellflame should it not be provided quickly enough. The last and seemingly third gate is kept closed unless one of a limited set of keys is used, though depending on which is another action required beyond it – else a mounting accumulation of power in a hidden enchantment will grow to trigger an alarm ward.
A great enchanted room, the Mirage is thought by Masego to be the first example of the sorcery that would come to replace scrying. 
The room itself is a circle of a mere two hundred feet in diameter. Effort has been taken so that not so much as a speck of the floor, walls and ceiling will offer magical interference with the sorceries meant to be worked within. For that reason the great round table at the heart has been made of stone. Around the table, exactly twenty armchairs of stone had been placed within boxes of glass just slightly apart from each other. Linked to the scrying pool hidden beneath the table, ropes of a dozen different purified metals – including grey adamant, which only the Gigantes know how to make – connect to different parts of the ritual arrays hidden under the floor of the seats, connected to the glass of the boxes through a superbly clever bridging enchantment of the Repentant Magister’s invention. The ritual arrays beneath the seats were designed by the Hunted Magician.
The result is a nearly perfect illusion carried by the glass: with the proper preparations made on both sides, anyone seated at the table of the Mirage would be within an illusion perfectly mimicking the immediate surroundings and individual of whoever was being scryed by the central ritual.
Users of the Mirage are instructed to wear simple clothes and no jewelry, and no weapons are allowed in. 
A part of the Chancel, the restricted stacks is warded and guarded.
The Forlic is meant to serve as the entertainment hub of all the men and women in the Arsenal. It is accessible only through the central halls of the Knot – as well as a discreet tunnel coming from the Alcazar. One section is essentially a sprawling tavern, another a private little brothel, a gaudy strip acts as a gambling house and there is a fighting pit tacked on. Callowans and Procerans were fond of dogfights, but the more exotic beasts Levantines liked to throw into pits had been deemed too expensive and dangerous for consideration. Duels and brawls, though, are allowed. Only to first blood and with healers in attendance. 
The fighting pit itself has a floor made of sand, with a rafter above it and has space to fit more than fifty people. Around the pit are benches and stairs leading down from the entrance of the pit.
The centre of the Arsenal, the Knot is a mess of winding hallways, messy and crowded crossroads that leads off to warded stairs.
Named for its stout build, low ceilings and the fact that it is where the leftovers of more important places ended up. The stone here is new and utterly bare, like it’d been conjured up out of thin air, and there is a scent in the air. Almost like metal, but not quite. While the scent is everywhere in the Arsenal, the smell is stronger here than anywhere else.
The Stacks of This and That
There are seventeen different repositories of books in the Arsenal. Several of the libraries were restricted to individuals assigned to official Grand Alliance projects and some held knowledge dangerous enough only a handful of people would ever be allowed to enter them.
The Stacks of This and That are originally meant to be the miscellaneous stacks, a dumping grounds for everything that doesn’t fit into another repository where even guards have access to. But turned into one of the largest rooms in the Arsenal and filled with little alcoves. Within is half a hundred little secret nooks where people can sit with a cup of something, hide for a secret talk or a fuck or even just a quiet nap.
There are broad open doors at the entrance, and a carving in the wall spelling out Miscellaneous Works Repository in three languages: Chantant, Lower Miezan and Ceseo. There was a bureau buried under an avalanche of books just past the doors, with 'department of this and that' written in chalk on the side of the door, as well as 'ring if you need a custodian, we would like one as well'.
The Stacks of This and That is larger than the throne room in Laure and every spare inch seems to be used by either stacks or wagon-sized wicker baskets filled with books not yet classed.
The magelight globes hanging from the low ceiling has been tied to tongs of leather in a way that made it so they could both be worn and used as a handheld lantern. They shine down on cramped but neat paths of shelves filled to the brim with books of all shapes and sizes, Chalk slates haphazardly distributed reveals some arcane library reference symbols and broad themes to swaths of the collection.
Capable of seating 400. Named typically sit and eat together in a corner, where most people avoid sitting.
Unnamed, unlike most areas of the Arsenal.
The Blind Maker's Workshop
Trashed when the Arsenal was invaded by the fae of the Autumn court. Sits between the Belfry and the Workshop in one of the hallways.
The Bitter Blacksmith's Workshop
Owned by Helmgard.
The Concocter's room
A potioneer’s brewing room with a small nook to sleep in.
To enter the Arsenal, one has to visit a boundary station and travel via translocation. The time it takes to get to the Arsenal from any boundary station, takes the better part of a day. Translocation never happens in less than six hours, and has to be initiated at the proper time.  One of the functional times for translocation is one hour before Noon Bell. 
One of the locations where a boundary station can be found is at Saregnac, in the Principate of Procer.
Within the Saregnac station, the ritual room for translocation is bare, and large enough to accommodate maybe a hundred people at a time. Rituals arrays, a tapestry of circles and squares and interlocked arcane shapes had been craved directly into the floor. 
The translocation process involves a short ritual, half an hour of incantations in sequence as the arrays were methodically powered. Translocation then takes place and the travellers are moved to an almost identical stone room in one of the mountains of the Twilight Ways.
The room's air has Twilight's freshness to it. The walls have arrowslits so that any intruder find the room a well-prepared killing ground. The corridor beyond is built with two things in mind: for supply wagons to be able to pass through and the ability to wage a stubborn defence against anyone entering through the array room. Spike-bearing steel bars could be brought down to anchor makeshift palisades, portcullises were set in the ceiling every thirty feet and runes and ritual arrays are carved into the walls, awaiting someone to wield them.
Another translocation is required. Typically, there will be several checkpoints to go through. However, it is possible to take a shortcut. The shortcut leads into the most heavily defended part of the Arsenal.
Lesser dimensional pockets between the Arsenal and everything else that had been grafted onto the Arsenal by the Witch of the Woods.
Within the Treshold, visitors will find themselves with a slab of stone standing surrounded by nothing. Walking forward brings out another slab to form a path, and after half hour of walking in a straight line, the traveller will reach a significantly larger slab, where a circle of silvery light the size of a door was hanging in the air. Activating the circle causes the circle to become a rectangular door anchored on the ground, allowing travellers to enter the Arsenal.
Stepping through the shortcut's door leads to an area in the Arsenal that also acts as a killing field for intruders. Flat stone grounds overlook by tall structures leading into corridors, bristling with soldiers and engines of war, with sorcery buzzing in the air, alongside wards and enchantments and half a dozen other things.