In July 2022, Crown Prince Mohammed bin Salman released a promotional video for The Line—a planned linear city stretching 170 kilometers across the Saudi desert, 500 meters tall, 200 meters wide, clad entirely in mirrored glass, housing nine million people, with no cars, no streets, no carbon emissions, and every daily necessity within a five-minute walk. The video was produced with the aesthetic confidence of a prestige television trailer and the engineering specificity of a fever dream. There would be flying taxis. Robot butlers. A sports stadium suspended 350 meters in the air. Vertical farms. Artificial intelligence managing the entire city like a cognitive organism. The prince called it “a civilizational revolution” and said it would be the most livable city on the planet “by far.”
Three and a half years later, construction on The Line is suspended.
The Saudi sovereign wealth fund paused work on September 16, 2025. The NEOM CEO quit. The 2029 Asian Winter Games, which were supposed to be held at Trojena—a ski resort built on manufactured snow in the Saudi mountains, another NEOM subproject—were indefinitely postponed in January 2026. The workforce has been cut by roughly 35 percent. Over a thousand employees have been relocated from the remote construction site to Riyadh. The sovereign wealth fund wrote down $8 billion from the project. Internal evaluations suggest the final cost of The Line alone could approach $9 trillion—not billion, trillion—which is roughly nine times Saudi Arabia’s annual GDP. And the Financial Times reported that MBS himself has now privately accepted that the original vision will be realized as something “far smaller.”
This is, by any objective measure, one of the most spectacular collisions between architectural ambition and physical reality in modern history. And the thing is, it was always going to end up here. The warning signs weren’t subtle. They were load-bearing.
What was actually proposed
The original specifications for The Line read like someone took a megastructure from a science fiction novel and submitted it as an engineering brief without checking whether the laws of physics had signed off. Two parallel mirrored walls, each 500 meters tall—roughly the height of One World Trade Center—extending 170 kilometers in a straight line from the Red Sea coast inland through desert valleys and over mountain terrain, with a 200-meter-wide gap between them containing a multi-layered city stacked vertically: residential, commercial, recreational, and transportation layers, all climate-controlled, all connected by automated transit, all powered by renewable energy.
The planned population density was 260,000 people per square kilometer. For comparison, Manila—the most densely populated city on Earth—has a density of roughly 44,000 per square kilometer. The Line, as designed, would be six times denser than the densest city that currently exists. And it would achieve this density not by building outward, as every city in human history has done, but by building upward and linearly, which creates engineering constraints that compound at every scale: structural loading, wind forces on a 500-meter-tall continuous surface, seismic risk in a region with active fault lines, thermal management in a desert where surface temperatures regularly exceed 50°C, water supply for nine million people in one of the driest regions on Earth, and the logistical challenge of moving millions of tons of construction material to a remote site with no existing infrastructure.
The cost estimate of $500 billion was, in retrospect, the most optimistic number in the history of optimistic numbers. An engineering analysis by Imperial College London noted that constructing The Line to its stated specifications within the proposed timeline would require building at 15,000 times the rate of normal U.K. construction. The volume of The Line’s enclosed space—roughly 17 billion cubic meters—at standard high-rise construction costs of about $1,000 per cubic meter implies a structural cost alone of $17 trillion. You don’t have to be a construction engineer to sense that the math wasn’t done before the video was shot.
What was actually built
The construction that did happen is not nothing—and this is the part that gets lost in the “it’s all a fantasy” narrative. Satellite imagery from late 2024 shows massive earthworks, completed buildings, grid-like infrastructure layouts, and support facilities along the western end of the route near the coast. The 170-kilometer trench that was excavated across the desert is visible from space. Concrete foundations have been poured. Vertical cores—the structural columns that will support the mirrored walls—have been started along the initial 2.4-kilometer “Phase One” section.
Phase One was always going to be the proof of concept: a small section near the Red Sea containing anchor assets—residential units, commercial space, a marina, and the foundations for the stadium—designed to demonstrate the concept and attract further investment. The work on that section is real, it’s substantial, and it represents an enormous expenditure of capital, labor, and engineering effort.
But Phase One is 2.4 kilometers out of 170. That’s 1.4 percent of the total length. And even that section isn’t complete. The cores are partially built. The steelwork for the outrigger beams hasn’t been installed. The mirrored cladding—the visual signature of the entire project—exists only in renders. The timeline for completing even this initial section is unclear, because construction was suspended in September 2025 and as of March 2026, work has not resumed.
Why it stalled
The proximate cause is money. Oil prices have been softer than Saudi Arabia’s budget requires, the sovereign wealth fund’s portfolio has underperformed, and the combined cost of Vision 2030’s megaprojects—of which NEOM is only one—has exceeded the kingdom’s ability to fund them simultaneously. When you’re also building the world’s tallest skyscraper in Jeddah, a massive entertainment city called Qiddiya with a Six Flags theme park, and dozens of other giga-scale developments, something has to give. The Line, being the most expensive and most speculative of the bunch, was the logical candidate for a strategic pause.
But the deeper cause is that the project was, from inception, designed backward. The vision came first. The engineering came second. The constraints came last—or, more accurately, never fully arrived. This is the pattern that every failed megaproject follows, from Fordlandia to the Concorde to the Superconducting Super Collider: you start with an inspiring image of the finished product, work backward to figure out how to build it, discover that the physics or the economics or both don’t cooperate, and spend years trying to close the gap between what you announced and what you can deliver before quietly scaling back and declaring the scaled-back version was the plan all along.
The specific engineering problems with The Line have been catalogued exhaustively by independent analysts. Pouring concrete at scale in a remote desert environment requires perfect consistency over long durations—too fast and the ingredients separate, too slow and it sets unevenly. The mirrored glass exterior would create a solar death ray effect, concentrating reflected sunlight onto the ground between the walls at temperatures that could melt asphalt. The structural loads on a 500-meter-tall continuous wall extending for 170 kilometers—including wind loading, thermal expansion, and seismic forces—exceed anything that’s been built anywhere on Earth. The water supply for nine million people in the Tabuk desert would require the largest desalination infrastructure ever constructed, in a location with no existing water infrastructure. Each of these problems is solvable in isolation. Together, at this scale, in this timeline, in this location, they compose something approaching impossibility.
What happens now
According to the most recent reporting, architects have been tasked with figuring out how to repurpose the infrastructure that’s already been built—the trench, the foundations, the cores—into something deliverable. The leading candidates appear to be a much shorter initial city section near the coast (the 2.4-kilometer Phase One, potentially extended to 5 kilometers) at a reduced height, with the remaining earthworks potentially repurposed for industrial use, including AI data centers. The coastal location is considered an asset—saltwater for cooling, proximity to shipping lanes, existing port infrastructure from the Oxagon industrial zone nearby.
The full 170-kilometer vision has been deferred to a “multi-decade timeline,” with 2045 cited as a possible completion date—though at current pace, independent analysts have projected full realization could stretch into the 2070s or 2080s, if it happens at all. The Mukaab, a massive cuboid building planned for another Vision 2030 project in Riyadh, has already been cancelled outright. Trojena’s Asian Winter Games have been indefinitely postponed. The broader NEOM ecosystem is being triaged: some components (Oxagon, the industrial port) appear viable; others (Trojena, Sindalah luxury island) are in critical condition.
What it actually tells us
The Line is not a story about Saudi Arabia being uniquely delusional. It’s a story about what happens when a planned city is designed as a marketing asset rather than an engineering project—when the render is more important than the spec sheet, when the announcement timeline drives the construction timeline rather than the other way around, and when the person commissioning the project has the authority to override every engineer in the room who’s trying to explain why the physics don’t work.
The historical record on planned cities built from scratch is not encouraging even under far less ambitious parameters. Brasília works but is widely considered sterile. Naypyidaw, Myanmar’s purpose-built capital, is a ghost town. Masdar City in Abu Dhabi, billed as the world’s first zero-carbon city in 2006, has been quietly scaled back to a small neighborhood. Songdo in South Korea, designed as a ubiquitous computing city, is roughly half-occupied a decade after opening. The pattern is consistent: planned cities that succeed tend to be modest in scope and flexible in design. Planned cities that lead with a grand vision and a promotional video tend to become very expensive lessons in the difference between rendering and reality.
The Line may still produce something useful. A 2.4-kilometer coastal development with advanced infrastructure and renewable energy systems would be a significant achievement, even if it bears almost no resemblance to the mirrored canyon city in the original video. But that’s the downgrade that reality imposes on ambition when the constraints weren’t named before the plan was drawn, and it’s a pattern as old as city-building itself.
We cover NEOM, The Line, and the full history of utopian megaprojects—from Fordlandia to Auroville to the kibbutz movement—across our Utopian Societies course. The pattern of visionary ambition meeting structural reality is the through-line of the entire course, and The Line is its most expensive modern example.