You’re standing at the rusted gates of the docklands, the salty air thick with the scent of damp wood and decay. Behind you, the city hums with life—voices calling across the piers, the rhythmic creak of ships shifting in their moorings. But ahead? A yawning stone archway, half-swallowed by ivy, leading down into darkness.
The steps beneath your boots are slick with algae. Somewhere ahead, water drips, echoing against unseen walls. The deeper you go, the closer the air presses in, stale and briny, heavy with the weight of things long buried.
This is the City Beneath.
This is an underworld.
And if you’re crafting your own, you want it to feel like this—like crossing a threshold into another world, one both thrilling and treacherous. Whether you’re writing a literal underground city (like the one in The Remnant) or just a metaphorical descent into the seedy underbelly of a society, the goal is the same: to make your readers feel like they’re walking those tunnels themselves.
So, let’s talk about how to do that.
"The City Beneath was a world of shadows and secrets, where the past wasn’t so much forgotten as buried alive, left to decay in the dark while life continued overhead."
Step One: Build Your Underworld, Layer by Layer
The best fictional underworlds don’t just appear—they evolve. In The Remnant, the City Beneath wasn’t planned. It was built over, each new generation entombing the last in layers of forgotten streets and abandoned corridors.
This organic history makes it feel real.
If you’re designing an underworld, think about:
- Why does it exist? Was it intentional (catacombs, sewers, secret tunnels) or accidental (abandoned ruins, collapsed infrastructure, nature reclaiming lost places)?
- How has it changed? The City Beneath was once part of the Cross-Sea Lands, but as the tides rose, people built higher. The lower levels became uninhabitable… until the desperate and the cunning moved in.
- Who lives there now? Not just physically, but socially. Is it a place of exile? A criminal haven? A hidden refuge?
And let’s be real—if your setting doesn’t have dripping water, flickering lanterns, and echoes stretching into the void, is it even a proper underworld?
Lore from The Remnant
At first, the Cross-Sea Lands were just a collection of dockside settlements, built close to the water for ease of trade. But the tides were relentless, rising higher each year, and so the people built up—stacking streets atop older ones, using the buried layers as foundations for the next. Over time, what had once been vibrant neighborhoods became sealed off, sunless corridors, abandoned as the city continued to expand.
But nothing stays empty forever.
The desperate moved in first—those too poor to afford homes in the rising city above. Then came the opportunists—smugglers and outlaws who thrived in the forgotten depths. And finally, the City Beneath took on a life of its own, evolving into a shadow society with its own rules, factions, and power struggles.
In The Remnant, the City Beneath wasn’t planned, but it became indispensable. Its tunnels now serve as smuggling routes, its ruins as safe havens for the displaced. The surface world depends on it, even as it pretends it doesn’t exist.
The City Beneath also still carries the marks of its past. Grand stone archways once led to noble houses, now nothing more than crumbling skeletons. Algae blooms in stagnant pools where fountains once ran clear. And in the deepest tunnels, where no light has touched for centuries, secrets remain untouched—waiting for someone brave (or foolish) enough to find them.
"A place where no light reached, where the past lay buried beneath centuries of stone and salt. The air was thick with the scent of brine and decay, and every step sent echoes stretching endlessly into the dark."
“Then came the sound of breaking glass, of shattering stone, of everything solid giving way at once . . . Basha’s last thought wasn’t of falling—it was of Chiko’s hand still gripping hers, refusing to let go even as the shadows rushed up to meet them.”
Step Two: Make It Dangerous
A good underworld isn’t just spooky window dressing—it’s a threat.
In The Remnant, the City Beneath isn’t just a place where criminals hide. It’s a living hazard.
- Floodwaters rise unexpectedly, swallowing entire corridors.
- Cave-ins are common, the weight of the city above pressing down.
- Darkness is absolute. If your lantern goes out, good luck finding your way back.
But the biggest danger? The people.
Enter the Whispering Grotto—a tavern where smugglers, mercenaries, and thieves trade more than just coin. Basha learns the hard way that down here, alliances are shaky, debts last a lifetime, and betrayal comes cheap.
So when you’re crafting your underworld, ask:
- What’s physically dangerous about it? Are there unstable walkways? Air that’s slowly poisoning people? Tunnels that shift?
- What’s socially dangerous? Who controls the underworld? What laws (or lack thereof) shape interactions?
- How does your protagonist survive it? Is it skill, luck, or sheer audacity keeping them alive?
Because if your underworld isn’t trying to kill your characters, you’re doing it wrong.
Lore from The Remnant
In The Remnant, Basha quickly learns that the City Beneath isn’t a place you can just navigate on instinct. It’s a world that punishes the overconfident. She nearly drowns when an unexpected tide rushes through a tunnel. She watches the ground vanish beneath someone who took a wrong step on rotting scaffolding. And when she finds herself lost in the dark, she realizes the most terrifying thing about the City Beneath isn’t what you see—it’s what you don’t.
A crumbling ruin built into the bones of an old temple, the Whispering Grotto is the one place in the City Beneath where everyone crosses paths. It’s not just a tavern—it’s a market, a battleground, a graveyard waiting to happen. Deals are made in hushed voices over stolen drinks. Debts are settled in dark corners with whispered threats or drawn knives. When Basha first enters the Grotto, she thinks she’s untouchable—her name carries weight in the world above. But she learns fast: names mean nothing here. The first lesson of the City Beneath? No one is safe. Not even her.
- The strong make the rules.
- The cunning survive.
- The desperate get used.
No one comes to the City Beneath without a reason. And no one leaves unchanged.
“Above her head, the paths of her ancestors rose in layers like the rings of a tree, each one marking another year the waters had tried to claim them . . . while the oldest streets lay sealed in the dark, carrying a legacy the powerful were happy to forget.”
Step Three: Use It as a Metaphor
The best settings aren’t just places—they mean something.
In The Remnant, the City Beneath is more than just a cool backdrop for smuggler showdowns and narrow escapes. It’s a reflection of the world above.
- The wealthy literally live above the poor.
- The powerful pretend the underworld doesn’t exist—until they need something from it.
- The City Beneath is a place of exile, but also of rebellion.
If your story has an underworld, use it to say something about your world as a whole. Does it represent the forgotten parts of society? The consequences of unchecked greed? The resilience of those cast aside?
A setting with meaning hits harder.
If you’re writing an underworld, ask yourself:
🔹 What does it say about your world’s social structure? (Who lives above vs. below?)
🔹 What secrets does it hold? (Lost knowledge? Forbidden truths?)
🔹 How does it challenge your protagonist? (Will they embrace the darkness? Or fight to rise above it?)
Lore from The Remnant
Centuries ago, the Cross-Sea Lands built upward with each new tide, but not everyone could afford to rise. As the noble houses constructed their manors on higher ground, whole districts were left abandoned beneath them. The people who remained were those without the means—or the influence—to climb higher.
In time, the City Beneath became a dumping ground for more than just old buildings. Political exiles, disgraced merchants, criminals—all were cast into the depths, left to fend for themselves.
The world above refuses to acknowledge the City Beneath. It’s an inconvenient truth, a stain on their illusion of order. But when they need something—contraband, a secret passage, an inconvenient rival disposed of—they come crawling back.
When Basha first descends, she’s stunned by what she sees—crumbling mansions and broken archways, evidence that this place was once just as grand as the city above. But now, the chandeliers have rusted, the courtyards have flooded, and those who still live here have learned to thrive in the ruins of what others have abandoned.
In The Remnant, Basha enters the City Beneath looking for a way out. But what she finds instead is a choice:
🔥 Ignore the truth she’s discovered and return to the life she knew.
🔥 Or use what she’s learned in the underworld to tear down the world above.
Because the thing about an underworld is . . .
Not everyone wants to leave.
Some want to drag the whole world down with them.
“Every stolen moment here was a rebellion against the weight of duty that had settled on her ever since Sara left—a mantle she’d never wanted, never asked for.”
Step Four: Make Your Characters Change Because of It
A great underworld isn’t just a place your characters visit. It’s a trial they have to survive.
For Basha, descending into the City Beneath isn’t just about hiding away from her responsibilities. It’s about stepping into a world where her family name means nothing. Where she has to earn her place. Where she learns, for the first time, that she’s capable of more than she ever thought possible.
So, ask yourself:
- What does your protagonist believe before entering the underworld?
- How does the experience challenge those beliefs?
- What parts of them die in the dark? And what parts are reborn?
The best underworlds transform the people who enter them.
Because in the end, survival isn’t about escaping the underworld.
It’s about becoming someone who can survive anywhere—even in the light.
Lore from The Remnant
Before she stepped into the darkness, Basha believed:
🔹 That power comes from status—from names, from alliances, from the weight of a family’s reputation.
🔹 That the world has rules—even if they are unfair, even if they serve the powerful, there is still a structure to them.
🔹 That she knows who she is—reckless but clever, privileged but capable, a fighter who never backs down.
She thinks she’s prepared.
She isn’t.
Everything Basha believed before is turned against her below.
🔻 Power doesn’t come from status—it comes from control. The City Beneath operates on a different kind of currency. Power is who owes you favors, who fears you, who knows your weaknesses and keeps them close.
🔻 The world has no rules—only those you enforce. If Basha wants to survive, she has to learn the new game fast. There’s no justice here. No safety net. No second chances.
🔻 She doesn’t know who she is—yet. Stripped of everything familiar, she starts to realize she’s more than just her family’s reckless disappointment. But who is she, if not the girl she used to be?
“She’d told herself she would forget, that she’d leave the darkness below and never look back. Yet the weight of those secrets clung to her like a damp cloak, refusing to be cast aside so easily.”
Step Five: Emerging into the Light
Eventually, your character has to leave the underworld (or at least try). And that moment—stepping back into the sun—should mean something.
- Maybe they emerge stronger.
- Maybe they’re carrying secrets that will shake the world above.
- Maybe they don’t want to leave at all.
But whatever happens, the underworld should linger. Basha may leave the City Beneath, but its shadows never fully leave her.
And that’s what makes a great underworld—not just its darkness, but the way it changes those who dare to walk it.
Lore from The Remnant
The City Beneath strips Basha down—but in that breaking, something new begins to form.
⚔️ What Dies:
- The belief that she can talk or bluff her way out of anything.
- The illusion that the world plays fair.
- The reliance on her past identity.
🔥 What’s Reborn:
- A new kind of power—one earned through action, not inheritance.
- The ability to read people in an instant—because one wrong read could mean death.
- A reckless kind of fearlessness—because she’s already lost so much, what’s left to be afraid of?
Final Thoughts
Now it’s your turn!
- What’s your favorite underworld in fiction? (Mordor? The Mines of Moria? Coruscant’s lower levels? The entire city of Camorr in The Lies of Locke Lamora?)
- Have you ever written an underworld into your own stories? How did you make it feel alive?
- What are your favorite underworld tropes—secret smuggler tunnels? Ancient lost cities? Catacombs filled with more than just bones?
Drop a comment below and let’s talk about it!
And if you’re intrigued by The Remnant and want to see the City Beneath in action, stay tuned—there’s plenty more where that came from.
Happy writing, and may your tunnels be dark, your lanterns flickering, and your exits just a little too far behind you.
