Best viewed through Stonesense as Overseer doesn't show windows, in the distance to the right is Tower Likot (all those blank spaces in the walls are where the windows are), it sits atop one of the barracks, the entrance to the hospital, the entrance to the armory/Fortress hall, houses some captured humans (friendly), has its own barracks and was built in response to a growing need of quickly-assembled housing caused by a maturing population of children. It also contains the tomb of Urist Likot Lion L. Thunen, a legendary marksdwarf who perished fighting fire imps in the magma forges, who gives the tower its name. To the left is the Brass Tower, built because I felt like building something like it. Made out of precious metals like brass, it's capped with the fair blue metal and an artifact door called Velasiv. It's 31zlvls tall, and I suppose could also qualify for being the tallest complete tower (and if so, it's been so for quite some time).
Right in the center is the fortified dome that surrounds the Moose Pit, and above it, the tower that has grown upon it. Engraved on each face of the tower (with exception to the holy east) is a symbol. On the south side, it's the symbol for a nobledwarf.
On the north side is a symbol for a sliver barb, which is the symbol for the Coincidental Portals, my Dwarves' civilization.
On the west side is a symbol of a Dwarf striking the Earth. The Dwarf has copper skin, malachite gemstone eyes and a beard of coal, which seems textured as gold here. Would have used emeralds for the eyes, but alas, the caravans cannot reach us anymore with their precious gemstones in tow.
Not pictured: Sheer number of statues and doors adorning the walls. That great big pit into the Earth is the Quarry Pit; it was dug far away from the first Dwarven outpost for a reason. It's primary purpose was not to yield stone or minerals (though it did do just that), it was dug to connect all three cavern layers to the surface. This was while I was still preparing for this to be an apocalyptic disposable Fort, mind you.
The rampway is nothing special, a simple, functional ramp down to the earth. Underneath the ramp lies the prison, to the right lies more prisons (it used to also have bees there, but they were moved into a safer part of the Fort to avoid being plundered by flying FBs). In hindsight I could've made a nicer spiral rampway, but it serves its purpose quickly and efficiently. Fighting on the ramp is near-sucide for just about everyone, I've lost a lot of good Dwarves to the magma below this way. In a form of religious sacrifice, many things are thrown into the magma as offerings, or as burials (for undead corpses mainly).
For creatures trying to ascend to the overworld from the depths below, the Rampway approach is lightly guarded, with exception to the spire right in the center of the Quarry. The spire can be filled with a dozen marksdwarves and also has a bridge connecting it to the corridor to the surface, just in case the corridor itself becomes unsafe to use. Things that get shot by the marksdwarves that are flying around/dodge into the magma pit tend to die horribly, be they living or undead.
Once they make it past the rampway (which tends to happen whenever marksdwarves don't make it to the spire in time), any cavern critters then have to make a 90 spans dash through the Quarry-surface corridor, which is guarded by chained-up plump helmet men sentries, war pigs, stone traps, cage traps, firing windows for marksdwarves and plenty of space to assemble a Dwarven army (with one of the Dwarven barracks being conveniently connected to the quarry corridor). About 3 dozen bridges doing various things are also linked up to shut down the hallway. Given how old they are though, they've never been used nor will they ever be used, as I'm not convinced that they'll only do what I think they'll do. Very much, a last resort 'shut everything down' precaution.
The corridor then leads to the final gatehouse to the overworld. Also on the left, that odd structure standing on top of the pillar is where the great prison housing the demons is being built.
The Memorial Broke, named so as it runs on the Brook and holds all the memorials of the Fort. The last of its walls are being put up, soon its exterior will be complete. Two giant stained glass windows (which you can't see in Overseer sadly) depicting the eye of armok and a dwarf looking through an adamantine tube let in light from the rising sun and the setting sun respectively.
Every Dwarf that dies here gets a masterwork memorial placed here on the north side, and every other notable foe or ally that falls in Silentthunders gets a memorial on the south side. The brook brings water to the soil of the first floor.
This in turn keeps a small park's worth of trees and plants alive in the memorials, with the most notable being an old willow at the end of the memorial path. It's a quiet place for Dwarves to relax, mourn and be free from the travails of normal Fortress life. A place to honour both the living and the dead.
Exterior of the Rodemdome, carved out of the stone layers. It's a massive dome made entirely out of gemstone windows, supported only by other windows - no floors or walls involved.
You can't see the dome but you can see where water is
not, making this cool effect. The Rodemdome was mainly built to allow my Dwarves to eat dinner in style, drinking fine spirits while they watch fish swimming all around them. It was also built to demonstrate breakthroughs in construction techniques. If you build a window on top of a wall, then deconstruct the wall beneath it - you create a freestanding window, allowing you to create a structure out of pure windows.
The Quarry Tree Gardens; formed after tetrahedrite strip mining had left massive and ugly scars in the ground, and I thought of ways to make the scars into something more aesthetically pleasing.
What the Hell Fort looks like. It's nothing particularly ornate, little more than a functional block and tunnel.
Inside the courtyard, which is just underneath the center of the sky depots in the overworld. It used to house the trade depots, but those were moved to the roof. Etched into the ground in ice and brass are strange symbols, and those symbols can be opened to the skies above by lifting the sky teeth, allowing them to be covered in Dwarf blood/snow. The courtyard now serves only its militaristic purpose; once enemies make it past the brass palisade and the murder holes of the tunnel, they enter this wide open expanse surrounded by marksdwarves on all four sides and melee dwarves right in front of them. Their only hope is to try and make it across open ground to the interior gate; it too is fortified and is also full of stone traps. From there they stand a better chance, of going up through the HQ (which has a lockable hatch and bridge mechanisms), or they can try to make it through the Citadel or Residency Hive, which are both Fortresses in their own right. Based off of the medieval architectural principle of making the enemy fight for the most advantageous position to die in.
Part of the Fortifications to the Citadel, it has its own moat inside the Fortress complex (owing to days when that area of the Fortress WAS the outside world). When the lever is pulled to defend the Citadel, one bridge raises creating a solid wall between the outer perimeter and the Citadel, the other bridge deconstructs and destroys itself.
If the worst comes to worse (overwhelming defeat occurs in the overworld), or if the threat comes from within the Fort (entirely possible given a zombie cascade or some great demon or megabeast invasion), then retreat to the dining halls is possible. This is possible because the dining hall is another Fortress. It currently has no fortifications for marksdwarves to use and its walls have been incomplete for decades, nevertheless, it is full to the brim with deadly traps. It also provides a long, treacherous route for enemies to take whilst allowing the Fort's melee Dwarves to effectively ambush them.
To get the full scale of the Fortress dining hall, note that this is only half of it (could only get a screenshot of it when overseer bugged out a bit), and that the Fortress Hall is larger than the Citadel and Hive combined.
The gigantic brass battle axe sitting atop the front entrance to the Fort. Originally meant to warn traders and diplomats that to insult Silentthunders with bad prices or words would be to incur horrific injury, now it only serves T̷͕̬͔͎͎̥̝̱͙̙̤̟̭̙̺̝̀̀̕Ḩ̬̲̻̙̝͡͡͝E̶͜͏̦̩̯̜̙̩̙̮͉͓̤͔̗̞̰̞̹ ̸̢̲͖̝̭̟̺̜̳̹̱͇̝͘͜ͅH̨̛̺͙͔̼͚͚̙͞A̵̧̹̮̦̯̗̗͈̭͎͓̜͇̞͘͟R͖͕͕̀́͢V̡̧̺̭̫̺̙͖̲̱̩͇̟͙̪̬̗̱̩̹̲É̷̢̬̘̜̺̜̬͕͍̣̱̮̩͖̜͎͓̲͍̬͠S̢̢͕̠̲̞̯̗̝͍̫̻͓͙͔͇̙̀͡ͅṮ̵̥̼̙̝̼͉̩̙̺͎̳