Polis's Walls

Lore & Background

The walls of Polis were raised by the first generation of ground-dwellers who emerged from the Ark, combining whatever construction materials they could salvage from the ruined surface with the engineering knowledge carried down from the station. The result is a structure that looks less like a single engineered fortification and more like a geological formation of human making: thick, layered, scarred with welding marks and patched with mismatched plating. The outermost ring is the lowest and broadest, serving as the first line of defense and the site of most gate traffic. Inner rings climb higher, closer to the central tower, reflecting the social stratification of the city itself.

The walls are never truly static in the narrative. In the early seasons they represent security and the promise that the old world's chaos has been walled away. As the series progresses, they become sites of conflict: the Sins of the Father arc and later external threats force the city to defend its perimeter in ways that expose how fragile the illusion of safety really is. Characters who climb the walls—whether to escape, to spy, or to attack—do so against the full weight of the city's authority, making the act of scaling them a deeply political gesture.

By the later seasons, the walls have been damaged, partially rebuilt, and in some sections repurposed. Their condition mirrors Polis itself: still standing, still imposing, but no longer the monolithic, untouchable structure it was when the first settlers raised them. They remain, however, the single most recognizable visual signature of the city and a constant reminder that in The 100's world, safety is always a matter of who holds the gate keys.

In Their Own Story

The wind off the irradiated plains carries a taste of metal and ash, and Clarke presses her back against the cold concrete of the outer wall, feeling the vibration of the city's generators humming through the stone beneath her palms. Below, the gate is sealed, the sentries' torches cutting thin orange wedges through the dusk. She can see the whole valley from up here—the dark smear of the dead forest, the glint of a river that might be poisoned, the distant shimmer of heat distortion where the old highways used to run. The wall is rough under her fingers, a patchwork of rivets and welded seams, and somewhere in its thickness she can feel the old world still trapped, the steel and rebar of a civilization that never thought it would need to hide behind a wall. She runs her thumb along a fresh scratch in the concrete—someone's blade, maybe a week old. The city thinks it's safe. The city always thinks it's safe. She pulls herself over the top and drops the last three feet into the dirt, and the wall swallows the sound behind her like a secret.

Reader's Guide

You learn to read the walls the way you'd read a face. The outermost ring is the broadest, a low, battered rampart of poured concrete and bolted steel panels. It's where the gates sit—three of them, each framed by a canopy of salvaged wiring and floodlights that never quite stay on. The gate guards rotate in shifts, and the line for passage can stretch for an hour if you're carrying goods. The concrete here is the oldest, cracked and weeping rust from the rebar inside, and the ground at its base is packed hard from years of foot traffic and vehicle treads.

Climbing inward, the rings step up in height. The second and third tiers are where the real defense lives: narrow walkways with crenellated tops, watchtowers at regular intervals, and the kind of layered steel plating that was clearly ripped from some old-world factory. The air up here is thinner, colder, and the wind off the plains hits you sideways. You can see the whole city spread out below—the central tower, the residential blocks fanning out in concentric rings, the farmland on the innermost edge. It looks orderly from up here. It doesn't feel orderly.

The innermost wall is the one most citizens never see up close. It's the thickest, the smoothest, and it wraps around the central district like a collar. The concrete here is newer, lighter in color, and the steel is clean. If you press your ear to it, you can hear the hum of the city's power systems running through the walls themselves. It's the part of Polis that's still being maintained, still being fed. The rest is just holding on.

Over the course of the series, you watch the walls change. New scars appear after each siege. A section of the outer ring gets patched with a different material, a different color, and it never quite matches. The gates get reinforced, then breached, then reinforced again. By the time the later seasons roll around, the walls are a palimpsest of every fight the city has survived, and the ones it hasn't.

Did You Know?

• The walls of Polis are constructed from a visible mix of salvaged and repurposed materials, reinforcing the show's theme of a civilization built on the wreckage of the old world.
• The physical act of scaling or breaching the walls is used repeatedly as a narrative symbol for defying Polis's authority and social order.
• The walls' condition visibly degrades and is patched across seasons, mirroring the political instability of the city they protect.
• The concentric, tiered design of the walls visually encodes Polis's class hierarchy, with proximity to the central tower representing higher status.