Somewhere beneath the mountains of Iran, right now, at this very moment, thousands of ballistic missiles are sitting in tunnels carved 500 m deep into solid rock. These are not ordinary military bases. These are entire underground cities with roads wide enough for trucks to drive through, automated rail systems that move missiles into launch position, refueling stations, power generators, command centers, and dozens of hidden exits scattered across miles of mountain terrain. And the most unsettling part is that no satellite, no spy plane, and no bunker-busting bomb on Earth can touch them. Iran calls them missile cities.
Western intelligence agencies call them one of the most complex underground military networks ever constructed by any nation in modern history. The commander of Iran’s Revolutionary Guard Aerospace Force once said something that sent chills through every defense ministry in the Western world.
“If we unveiled a missile city every single week, it would take more than 2 years to show them all.”
Now, here is where it gets even more intense. How did a country under crippling international sanctions, cut off from Western technology, isolated from global financial systems, manage to build hundreds of these underground fortresses across every single province in the country? How did they dig thousands of kilometers of tunnels through some of the hardest mountain rock on the planet? And how did they develop a system that can launch five ballistic missiles from a single underground silo in rapid succession, something no other country in the world has ever done? Those are the questions we are going to answer today. Now, let us go underground.
Chapter 1. Why Iran went underground.
To understand why Iran spent four decades building an entire shadow military infrastructure beneath its mountains, you have to go back to the 1980s. The Iran-Iraq War, which lasted from 1980 to 1988, was one of the most devastating conflicts of the 20th century. Iraq, backed by Western powers and armed with advanced weapons, launched relentless air strikes against Iranian cities. Tehran, Isfahan, Shiraz, and dozens of other population centers were bombed repeatedly. Iranian military installations on the surface were destroyed with ease. The Iranian leadership learned a brutal lesson during that war. Anything you build on the surface can be destroyed. Anything visible from the sky is a target. If Iran wanted to survive a future conflict against enemies with vastly superior air power, it could not rely on surface-based defenses. It had to go underground.
In 1984, while the war with Iraq was still raging, Iran built its first underground missile base near the city of Kermanshah. The base was designed to hide Scud missiles that Iran had acquired from Libya and North Korea. It was crude by today’s standards, but it established the fundamental principle that would guide Iranian military strategy for the next 40 years. Hide your weapons where the enemy cannot see them. After the war ended in 1988, Iran launched what it called the passive defense initiative in 1989. This was not a weapons program. This was a construction program. The idea was simple but radical. Iran would relocate its most sensitive military facilities, missile stockpiles, and command infrastructure deep inside the mountain ranges that stretch across the country. The Zagros Mountains in the west, the Alborz Mountains in the north, and ranges in the south near the Strait of Hormuz all provided ideal natural fortresses. Hundreds of meters of solid rock overhead meant that no conventional bomb, and possibly not even a nuclear weapon, could penetrate to the facilities below.
Over the next two decades, this initiative grew into one of the largest underground military construction projects in human history. Iran subterranean military nation, province by province, mountain by mountain, tunnel by tunnel. The logic was driven by cold strategic reality. Iran is surrounded by American military bases in virtually every direction. The United States has bases in Qatar, Bahrain, Kuwait, Iraq, Afghanistan, Turkey, and across the Persian Gulf. Israel, Iran’s primary adversary, possesses one of the most advanced air forces in the world. Iran knew it could never match American or Israeli air power in a conventional conflict. It could never win a dogfight or an air superiority battle. Its only chance of survival was to make sure that even after the most devastating first strike imaginable, it would still have enough weapons hidden underground to launch a devastating counterattack. That is the doctrine that created the missile cities.
Chapter two. Inside the missile cities.
So, what exactly is a missile city? Based on satellite imagery, leaked videos, and analysis by military experts around the world, these facilities are far more complex than simple tunnels or bunkers. They are fully self-contained underground military complexes with infrastructure that rivals some small cities on the surface. The typical missile city is carved deep into a mountain range. The tunnels can extend for kilometers with multiple branches, chambers, and levels. Some are estimated to be wide enough for two large trucks to pass each other comfortably. The ceilings in the main tunnels are high enough to accommodate ballistic missiles standing upright on their mobile launcher vehicles. Inside these tunnels, missiles are stored on road mobile transporter erector launchers, which are essentially massive trucks designed to carry, transport, and fire ballistic missiles. These launcher trucks can drive through the tunnels, exit through one of several concealed openings in the mountainside, set up in a launch position, fire, and then retreat back underground before enemy aircraft or satellites can respond.
But Iran has taken this concept much further than any other country. In 2020, footage emerged showing an automated underground rail system inside one of these missile cities. Ballistic missiles were shown standing upright in what can only be described as an underground magazine system. Five Emad medium-range ballistic missiles were visible on a single rail car positioned for vertical launch. The rail system moves the missiles through the tunnel to a launch shaft. When one missile is fired, the rail system automatically moves the next one into position. This allows Iran to fire multiple missiles from a single underground silo in rapid succession, one after another, like rounds from a magazine-fed weapon. This is something no other country has demonstrated publicly. In the United States, Russia, and China, each underground silo typically holds a single intercontinental ballistic missile. Iran’s system operates more like an automated launcher that can sustain a continuous barrage from a concealed position.
Each missile city is reported to have its own independent power supply, likely diesel generators that can operate even if the civilian power grid is destroyed. There are fueling stations inside the tunnels where liquid-fueled missiles can be prepared for launch without ever being exposed to the surface. Ventilation systems keep the air breathable for the soldiers and technicians who operate the facilities. Communication systems allow the bases to coordinate with Iran’s central military command. The entrances to these facilities are the most vulnerable point, and Iran has designed them accordingly. Each missile city has multiple entrances and exits, sometimes dozens, spread across wide areas of mountain terrain. These entrances are covered with concrete and soil to blend with the surrounding landscape. From satellite imagery, they look like natural terrain. If one entrance is destroyed in an airstrike, the others remain functional. The tunnels inside connect them all, so the loss of any single access point does not the base.
In March 2025, the video showed Iran’s armed forces chief of staff, General Mohammad Bagheri, and the IRGC Aerospace Force Commander riding through massive tunnel systems lined with launcher vehicles carrying advanced missiles. The footage revealed an enormous diversity of weapons stored in a single facility, including Hayber Shekan and Haj Qassem solid-fuel ballistic missiles, Ghadr H and Emad liquid-fuel ballistic missiles, Sejjil medium-range missiles, and Javeh land-attack cruise missiles. In a single video frame, at least 78 missiles were visible, and the tunnels extended far beyond what the camera could capture.
Chapter 3. The underground Air Force and Navy.
The missile cities are just one piece of Iran’s underground military network. Iran has also built underground airbases, underground naval bases, and underground drone facilities, creating a military infrastructure that is almost entirely hidden from the surface. The most famous underground airbase is the Oghab 44 facility, located in the mountains north of the Strait of Hormuz in the province of Hormozgan. Construction began in the 2010s, and the base was publicly revealed just a few years ago. It is designed to house manned fighter aircraft, including F-4 Phantoms and F-5 fighters, and to service them to ensure full operational capability. The base has runways, maintenance hangars, fuel storage, and weapons depots, all built inside the mountain. This is critical because Iran’s air force is built largely around aircraft from the 1970s, dating back to the era before the Islamic Revolution, when Iran was a close ally of the United States. These aircraft are irreplaceable. Iran cannot buy new Western jets because of sanctions, so protecting the ones it has is a matter of national survival. During the June 2025 conflict with Israel, the Iranian command moved its most valuable aircraft into underground shelters before the strikes began. The result was remarkable. In 2 weeks of hostilities, only one operational F-5 fighter was destroyed.
Iran has also constructed underground naval bases along the coastline of the Persian Gulf and the Gulf of Oman. These bases house Iran’s fleet of small fast attack boats and missile boats. Iran’s naval strategy relies on what military analysts call a mosquito fleet, hundreds of small maneuverable boats that can swarm larger enemy vessels, launch missiles, and retreat into hidden harbors carved into the coastline. The underground naval bases allow these boats to be hidden, resupplied, and launched without ever being visible from the air. Quite large reconnaissance and strike drones are also housed underground with the necessary infrastructure in place, including airfield access, protected service stations, and weapon storage. Iran’s Shahed series drones, which have gained international attention for their use in various conflicts, are stored and launched from these underground facilities. The scale of this underground construction is staggering. When you add up the missile cities, the airbases, the naval bases, and the drone facilities, Iran has essentially built a parallel military infrastructure that exists entirely beneath the surface. The country you see from a satellite is not the country that fights back. The real military power is hidden underneath.
Chapter 4. How they built it all under sanctions.
One of the most remarkable aspects of Iran’s underground construction program is that the vast majority of it was built while the country was under some of the most severe economic sanctions in modern history. Western sanctions have restricted Iran’s access to advanced technology, heavy machinery, construction equipment, and financial systems for decades. So, how did Iran manage to build hundreds of underground military complexes without access to the tools and technology that most countries take for granted? The answer lies in a combination of factors. First, Iran has significant domestic expertise in civil engineering, mining, and tunnel construction. The country’s geography, with its vast mountain ranges, has always required sophisticated tunneling for roads, water systems, and railways. Iranian engineers have been building tunnels through mountains for civilian purposes for over a century. The same techniques and expertise were adapted for military use.
Second, Iran received critical early assistance from North Korea. In the 1990s, Pyongyang reportedly shared tunnel and silo construction technology with Tehran. North Korea is one of the world’s leading experts in underground military construction, having built extensive tunnel networks throughout the Korean Peninsula for decades. This technology transfer gave Iran a foundation to build upon. Third, China has been a quiet, but significant contributor. Chinese construction companies and engineering firms have been involved in various infrastructure projects in Iran, and the overlap between civilian and military tunnel construction is considerable. More recently, reports have indicated that Iran is using Chinese supply chains to obtain materials and components needed for its ongoing underground construction and missile programs. Fourth, Iran invested heavily in training its own engineers and developing its own construction machinery. When foreign contractors withdrew due to sanctions, Iranian companies stepped in. The same pattern that played out with Iran’s Tehran North Freeway, where Chinese and South Korean contractors left and Iranian firms completed the work, played out on a much larger scale with the military underground program. The construction methods themselves are a combination of traditional mining techniques and modern engineering.
Drill and blast methods are used to excavate hard rock. Tunnel boring machines, some domestically manufactured and some acquired through intermediaries, are used for longer, more uniform sections. The excavated rock and debris are dispersed over wide areas to minimize the visible signature from satellite surveillance, though military analysts note that completely hiding the construction of such large facilities is impossible given modern satellite technology. What makes the program resilient is its sheer scale and distribution. Even if intelligence agencies can identify some facilities, the network is so extensive and spread across so many provinces that destroying all of them would require a sustained campaign of thousands of strikes, something that would be extraordinarily difficult even for the most powerful military in the world.
Chapter 5. The test of war and what comes next.
Everything Iran built underground was put to the ultimate test during the conflicts of 2024 and 2025. In October 2024, Israel conducted strikes against Iranian military infrastructure. Then in June 2025, a 12-day war erupted between Iran and Israel with the United States also striking Iranian nuclear facilities. These were the first times that Iran’s underground fortifications faced real large-scale military attack. The results were telling. Israeli and American strikes caused significant damage to surface facilities. Air defense systems, some missile launchers, and nuclear infrastructure that was above ground or at shallow depths were hit hard. By some estimates, about 2/3 of Iran’s ballistic missile launchers and between 1/3 to 1/2 of its ballistic missile arsenal were destroyed or damaged. This was a devastating blow. But the underground infrastructure survived. Satellite imagery analysis indicates that the damage of ground-left bases temporarily inoperable at the surface level, but the assets hidden in the underground complexes likely survived completely.
Iran’s passive defense chief stated that the priority given to aerospace and missile assets guided 20 years of planning for the missile cities and depots built into mountains. He said only minor repairable damage occurred at some access points. Iran responded during the 12-day war by launching over 500 ballistic missiles at Israel in the span of a single week. The fact that Iran still possessed the ability to launch that volume of missiles after sustaining major strikes proved that the underground infrastructure had done exactly what it was designed to do. It preserved enough capability for a devastating counterattack. In the aftermath, Iran has accelerated its underground construction. Satellite images show tunnel entrances at nuclear sites being buried under soil and concrete. New protective structures described by analysts as concrete sarcophagi are being built over sensitive facilities. Mountain tunnel entrances near enrichment sites are being hardened and reinforced. The Iranian military has stated that its missile program advanced by several years as a result of the lessons learned from the conflict. The deputy head of the IRGC stated that Iran’s arsenal is now full and that the country has more than 30 types of missile and defense systems. The passive defense chief said that the shadow of war was present from the very beginning of their activities and that sensitive sites were designed from the start to be located in secure underground locations beneath mountains.
Iran’s underground construction is not slowing down. It is accelerating. The country’s building deeper, stronger, and more distributed facilities than ever before. The goal is to ensure that no matter what strikes it absorbs, no matter how many surface facilities are destroyed, the ability to retaliate will remain intact hidden beneath hundreds of meters of mountain rock. For Iran’s adversaries, this creates an almost impossible strategic dilemma. You can bomb what you can see, but how do you destroy what you cannot find? How do you neutralize hundreds of facilities spread across thousands of kilometers of mountain terrain buried so deep that the most powerful conventional bombs in the American arsenal cannot reach them. That is the question that keeps military planners in Washington, Tel Aviv, and Riyadh awake at night. And that is the story of how Iran, a country under sanctions, isolated from the world, built one of the most extraordinary underground military networks in human history. Hundreds of missile cities hidden inside mountains across every province stocked with thousands of missiles protected by hundreds of meters of solid rock and connected by tunnels stretching for thousands of kilometers. It is one of the most ambitious military construction projects the world has ever seen and most people have never even heard of it. And that brings us to the end of this incredible story.
