For more than a year, U.S. strikes have left a heavy footprint on Iran’s nuclear program. Facilities have been destroyed, critical infrastructure has suffered severe damage, and Tehran’s stockpile of highly enriched uranium—what Donald Trump calls “nuclear dust”—is believed to lie buried under rubble and tons of debris.

And yet, within this landscape of destruction, there is one site that remains almost untouched. A place that has not been struck—not because it is considered unimportant, but because it may be too difficult to destroy. This is Pickaxe Mountain—an underground installation inside Iran, which experts believe is buried so deep that even the most powerful American bunker-busting bombs may not be enough.

That is precisely what makes it so dangerous. Not only as infrastructure, but as an idea. As possible proof that even the most intense military campaign may not be enough to definitively stop Iran’s nuclear trajectory.

The facility that inspires fear even before it is completed

Experts do not believe Pickaxe Mountain is fully operational yet. However, their concern is not limited to the present—it is mainly about what this site could become.

If completed, the facility could provide Tehran with a production site for nuclear material—or even weapons—virtually immune to airstrikes. In essence, a place where Iran could attempt the final leap toward weapons-grade enrichment, knowing that the ability to neutralize it from the air would be extremely limited.

It is no coincidence that, as the United States escalated its operations, voices favoring a more aggressive strategy urged the White House to consider even extreme scenarios—from deploying special forces on the ground to plant explosives, to more unconventional and controversial ideas such as using chemical agents to render the facility inoperable.

Opposing these views, other analysts—closer to a deterrence-through-negotiation approach—argue that Pickaxe Mountain reveals something deeper: that military power, no matter how overwhelming, cannot by itself solve Iran’s nuclear issue.

The point where “hawks” and pragmatists agree

Here lies the paradox. They disagree on almost everything—war, deterrence, the limits of pressure, whether Donald Trump acted correctly or dangerously. Yet there is one point of broad convergence: any agreement with Tehran, if one is reached, cannot leave Pickaxe Mountain out of the equation.

In other words, whether one believes in force or diplomacy, the conclusion is similar. If this underground complex remains available, accessible, and active, then any claim of definitively curbing Iran’s nuclear program will remain incomplete.

This explains why this particular mountain has become central to discussions about the “day after” in the Iranian dossier. Not because it is the only problem, but because it may be the most difficult one.

What is known about Pickaxe Mountain

Very little has been publicly confirmed about the facility, which is locally known as Kuh-e Kolang Gaz La. Nevertheless, satellite images released last autumn recorded progress in construction, shortly after U.S. forces struck Iran’s three main nuclear sites in June.

This activity was seen by many as critical evidence. Donald Trump himself cited it publicly in a speech in April, arguing that Tehran had not abandoned its nuclear ambitions but was attempting to relocate them elsewhere, under new security conditions.

For many analysts, this reference left little doubt: the target was Pickaxe Mountain.

Deeper than Fordow, harder than anything struck before

The comparison that constantly arises is with Fordow—Iran’s underground uranium enrichment facility built into a mountainside, long considered one of the hardest targets in Iran’s nuclear network.

Fordow was struck with 30,000-pound Massive Ordnance Penetrators—bombs specifically designed to penetrate fortified underground installations. Yet, according to expert estimates, even these may not be sufficient for Pickaxe Mountain.

The reason is depth. The facility is believed to lie roughly 2,000 feet deeper within granite rock than Fordow. In practical terms, this means something both simple and alarming: the United States may possess the most powerful conventional arsenal in the world, yet lack a guaranteed way to neutralize such a target purely from the air.

This is the strategic problem in its purest form.

From centrifuge plant to potential hub of military enrichment

When construction began in 2020, Iran stated that the facility would be used to produce centrifuges—the machines required for uranium enrichment—to replace another unit that had been destroyed, likely by Israeli sabotage.

That is Tehran’s official version. However, skepticism remains strong, mainly because Iran has not allowed the International Atomic Energy Agency access to the site.

And when inspection is absent in such a critical location, suspicion grows significantly. For this reason, many experts consider it likely that Pickaxe Mountain is not intended merely for industrial support of the nuclear program, but for something far more serious: the stage at which enrichment reaches levels suitable for military use.

If that is the case, then this is not just another facility—it is a potential safe haven for the most dangerous phase of Iran’s nuclear cycle.

The uranium that may already be there

There is also a second, even more concerning dimension. Some experts fear that Iran may have already transferred part of its stockpile of highly enriched uranium to Pickaxe Mountain.

This is crucial. If the site is not merely a future installation but already a storage location for sensitive material, then the equation changes. Any military action becomes far more complex. The risk of burying the material under debris, making its removal difficult, or creating new operational problems after a strike increases dramatically.

Rafael Grossi has stated that he believes about half of Iran’s stockpile of highly enriched uranium is buried in Isfahan—one of the sites that was struck. He has not specified where the rest is. And this very uncertainty fuels fears that some of it may have been moved to an even more secure depth.

Why it has not been struck so far

The question arises almost automatically: if Pickaxe Mountain is so concerning, why hasn’t it been bombed?

The answer is not simple, but appears to have three levels.

The first is technical: the site may be so deep that an airstrike cannot ensure the destruction of its core.

The second is operational: a strike causing major collapses could complicate any subsequent inspection, material removal, or physical neutralization.

The third is political-strategic: when a target cannot be cleanly and definitively destroyed, any decision to attack risks creating more chaos than resolution.

This is what makes Pickaxe Mountain such a unique problem. It is not just a difficult target—it is one that may not lend itself to a “clean” military solution.

The ground operation scenario and its limits

This is why the idea of a ground operation resurfaces from time to time. The logic is that only forces on the ground—with engineers, explosives, and time—could attempt to truly disable the facility.

In theory, it sounds straightforward. In practice, it is extremely dangerous.

The site lies deep inside Iran, near Natanz and several hundred kilometers south of Tehran. To reach it, U.S. forces would need to penetrate deep into Iranian territory, exposing helicopters, transport aircraft, and personnel to ground fire, missile attacks, and drones.

And the challenge does not end upon arrival—it begins there. Such a mission would require time on the ground, reconnaissance, explosive placement, internal assessment, and potentially multiple waves of support—all within a hostile environment, with Iran having every incentive to turn the operation into a trap.

In simple terms, the scenario is not impossible—but it is extremely costly, politically and militarily.

Diplomacy as the only realistic way out

This is why even many critics of Trump’s strategy conclude that the only realistic solution ultimately lies in diplomacy.

Not because they underestimate the risk—quite the opposite. They consider it very real. But they believe that without Tehran’s cooperation, there is no safe, verifiable, and permanent way to neutralize such a facility.

Iran has previously agreed to disable critical nuclear assets—as in the case of the Arak reactor under the 2015 deal. This precedent shows that physical neutralization is not unthinkable. But it also shows something else: such actions require agreement, oversight, verification, and political will.

If any of these elements is missing, the problem returns.

Isfahan also in focus—but Pickaxe remains the priority

Pickaxe Mountain is not the only underground facility raising concern. Tehran has also declared a new enrichment unit in Isfahan, to which inspectors have not had full access.

There, too, estimates suggest the depth may exceed the effectiveness of bunker-buster strikes. However, the difference is that significant damage has already been recorded at tunnel entrances in Isfahan. By contrast, Pickaxe Mountain remains more functionally accessible—for Iran itself.

Combined with the ongoing activity seen in satellite images—trucks, concrete mixers, excavators, cranes, and fortification works—this strengthens the view that it represents the most pressing concern today.

The real message of Pickaxe Mountain

Ultimately, Pickaxe Mountain is not just another secret facility. It is the point where the illusion of an easy solution collapses.

For those who believed Iran’s nuclear program could be ended with bombs alone, this mountain is a stark reminder of the limits of air power. For those who insist that diplomacy without strict oversight is enough, it is an equally harsh warning that Tehran will continue to seek security, depth, and time.

In that sense, Pickaxe Mountain is more than a target. It is the ultimate test of seriousness for any future agreement with Iran.

If it is left out, the deal will feel incomplete. If it is not controlled, the problem will simply be pushed deeper—both literally and politically. And if someone tries to solve it by force alone, they may discover that the most difficult opponent is not always Iran’s intent—but geology itself.