هذا التقرير متاح أيضًا بـ العربية
Pickaxe Mountain reflects a shift in how Iran protects its nuclear program, following a series of sabotage operations and US and Israeli strikes that have targeted its facilities since 2020.
What began as a fortified facility for assembling centrifuges after a similar center in Natanz was destroyed in 2020 evolved over six years into a vast tunnel complex surrounded by walls and security installations, with its entrances covered by concrete, rock and earth, at a site adjacent to one of Iran’s most important uranium enrichment centers.
While Tehran has identified the project’s declared function as manufacturing and assembling advanced centrifuges, the scale and depth of the tunnels, along with the absence of international inspections, have opened the door to estimates about more sensitive uses, including storing equipment or preparing new enrichment capacity.
The site returned to the spotlight on July 13, 2026, when said US President Donald Trump during an interview that the mountain was a potential target for a direct strike at its entrance, before concluding by saying, “We will wipe out Pickaxe Mountain. Tell the Iranians to be ready.”
The threat came after Natanz, Fordow and Isfahan had previously been subjected to US and Israeli attacks, while the mountain complex remained outside the circle of direct targeting. The question centers on whether the United States can turn its threat into the actual destruction of a facility whose parts are estimated to lie beneath more than 100 meters of rock cover, while maps of the tunnels and internal halls remain outside the public domain.
Where is the mountain, and how was it fortified?
The mountain is located in Isfahan province in central Iran, directly south of the Natanz nuclear complex and about 220 kilometers south of Tehran.
Open maps place it about 2.5 kilometers from Natanz, making it more of a geographic extension of the facility than a separate nuclear site. Its summit rises to about 1,608 meters above sea level.
Fordow lies about 146 kilometers away by air, while the Isfahan nuclear center is roughly 126 kilometers away, according to approximate calculations, placing the mountain at the heart of the nuclear belt that includes the main enrichment, conversion and storage facilities in central Iran.
The local name appears on maps in forms close to “Kūh-e Kolang Gaz Lā,” where “Kūh” means mountain in Persian, while “Kolang” refers to a pickaxe or mattock.
The modern story of the project began on July 2, 2020, when an explosion and fire destroyed a large part of Iran’s centrifuge assembly center inside Natanz. The building was designated for assembling advanced centrifuge models used to raise uranium enrichment levels.
The Institute for Science and International Security, a US research center specializing in nuclear proliferation and satellite image analysis, estimated its design capacity at about 6,000 advanced machines annually.
On Sept. 8, 2020, announced Ali Akbar Salehi, then head of the Atomic Energy Organization of Iran, that Iran had begun building a hall that was “newer, bigger and more comprehensive in the heart of the mountain near Natanz,” linking the decision to the sabotage that struck the previous facility.
Salehi’s statement defined the project’s original function as replacing the centrifuge assembly center, while at the same time revealing an Iranian move to shift sensitive facilities from surface buildings to halls protected more effectively by layers of rock.
That trend was reinforced after the attack that hit Natanz’s power network on April 11, 2021. Tehran described the incident as “nuclear terrorism,” and the power outage caused damage inside enrichment halls and to centrifuges.
Satellite images in late 2020 and 2021 began to reveal the expansion of excavation work south of Natanz, the appearance of large piles of extracted rock, and the construction of roads and work areas at the foot of the mountain.
In a report issued on Jan. 13, 2022, the Institute for Science and International Security concluded that the volume of spoil and the length of excavation routes pointed to a larger and deeper complex than expected, with internal space that could exceed the needs of a simple centrifuge assembly hall.
The site consists of two separate complexes within a single security perimeter. The new complex includes two pairs of entrances, one on the eastern side and the other on the western side, and the four entrances lead to routes excavated beneath the mountain ridge.
As for the smaller complex, work there first appeared in 2007, and its entrances were later reinforced and rehabilitated in recent years. Images from 2025 showed the construction of a fence, a security wall and a patrol route encircling the base of the mountain and encompassing both complexes, directly connected to the security perimeter of the Natanz facility.
On July 31, 2024, the Institute for Science and International Security published an analysis of images showing what was likely a ventilation shaft site near the eastern entrances, along with an ascending road and power lines that turned into buried cables as they approached the area. It said these installations were consistent with the operating needs of underground industrial halls, while their function could not be confirmed from images alone.
During 2025 and 2026, protective work around the site expanded. Images from April 2025 showed a new security perimeter linked to the Natanz fence, while images from February 2026 revealed concrete being poured over extensions of some gates, the addition of concrete structures, and rock and earth being pushed over the entrances.
In a report published on July 14, 2026, the institute estimated that the complex remained under construction and had not entered full operation, based on the nature of the movement and equipment visible above ground. Satellite images do not allow a determination of what has been installed inside the halls or how operationally ready they actually are.
Estimates of the facility’s depth are based on the differences between the elevation of the entrances and the mountain ridge. According to published calculations, the western entrances sit at an elevation of about 1,512 meters, while the eastern entrances are at about 1,445 meters, and the rocky ridge above them reaches roughly 1,590 meters.
These figures produce a vertical difference of about 78 meters above the western route and 145 meters above the eastern route, assuming the tunnels extend horizontally. Other analyses used different measurement points and estimated the rock cover above parts of the complex at about 100 meters or more.
These figures reflect the amount of potential rock cover above the tunnel routes, while the actual depth of the halls remains tied to the slope and direction of the tunnels and the locations of the internal voids.
What do the tunnels hide, and why do they matter to Iran?
A centrifuge assembly facility remains the only function Iran has explicitly declared. Moving this capability inside the mountain gives Tehran a better-protected facility for producing advanced machines and replacing those damaged by sabotage or bombing, a role that has taken on particular importance after the damage inflicted on assembly and enrichment centers since 2020.
The scale of the project, its protective walls and the breadth of its entrances have raised suspicions about uses beyond assembly. In a report in January 2022, the Institute for Science and International Security raised the possibility that space inside it had been allocated for an enrichment facility relying on advanced centrifuges, based on the size and depth of the tunnels and information it attributed to a Western intelligence official.
The report kept that possibility within the realm of estimation, however, as there were no internal images or inspection results that would allow the nature of the halls and their equipment to be determined.
The institute also raised the possibility that the smaller complex dating back to 2007 could be used to store centrifuges or sensitive equipment, and perhaps materials linked to the nuclear fuel cycle. These were analytical scenarios not confirmed by inspections or images from inside the tunnels.
International access to the site remained absent, and the International Atomic Energy Agency did not publish information indicating that it had conducted inspections inside the two tunnel complexes.
The institute said IAEA inspectors had not entered the site, while the agency continued to demand that Iran provide more information and broader access to facilities and materials linked to its nuclear program.
The monitoring gap widened after the June 2025 war. In the same month, the agency confirmed that Natanz, Fordow and Isfahan had been hit by US strikes, then withdrew its inspectors from Iran at the end of the month for security reasons.
On July 2, Iranian President Masoud Pezeshkian signed a law suspending cooperation with the agency, before limited teams returned to the Bushehr plant during August. Access to the damaged sites and the fate of nuclear equipment and materials remained among the issues raised by IAEA Director General Rafael Grossi during 2025 and 2026.
On July 21, 2026, the newspaper The Wall Street Journal published an investigation citing Israeli and US officials as saying that Israeli intelligence believes Iran moved thousands of centrifuges into the Pickaxe Mountain tunnels during the fall of 2025, after attacks targeted its main sites.
The investigation said that “Israel” shared its assessment with the United States and that US authorities reviewed the information presented to them.
If true, the Israeli account gives the site a different significance, transforming it from a project under construction into a storage site housing ready equipment that could help Iran restore its enrichment capacity after any strike.
The published information does not reveal whether the Israeli assessment concerns the entire new complex, completed parts of it, or the smaller complex dating back to 2007. Nor does moving equipment for storage necessarily mean the facility has entered the stage of full industrial operation.
These possibilities explain the value the site acquired after Natanz, Fordow and Isfahan were targeted. If its use is limited to assembling centrifuges, it provides Iran with a fortified capacity to replace damaged equipment. The Israeli account about moving thousands of machines into the tunnels, meanwhile, raises its potential importance in rebuilding enrichment capacity. The complex’s actual contents remain beyond public verification by the International Atomic Energy Agency.
Can Washington destroy it?
Washington possesses the GBU-57 Massive Ordnance Penetrator, the heaviest US conventional munition designed to strike deep, hardened facilities. The US Air Force describes it as a weapon designed to reach and destroy buried weapons of mass destruction facilities, and its total weight is about 30,000 pounds.
Its actual ability to penetrate rock and concrete, however, remains among the military details not publicly disclosed, preventing a definitive numerical comparison between it and the rock cover above the Pickaxe Mountain tunnels.
Washington used the bomb in combat for the first time during Operation Midnight Hammer on June 22, 2025. And said Chairman of the Joint Chiefs of Staff Gen. Dan Caine the day after the operation that seven B-2 Spirit stealth bombers took part in the attack.
He explained that US forces dropped 14 GBU-57 bombs on the Fordow and Natanz areas, while more than 20 Tomahawk cruise missiles were launched at facilities in Isfahan.
Pickaxe Mountain presents a different engineering challenge because the tunnel maps, the locations of the halls and their internal levels are unknown. The circulated figures for rock cover, which may exceed 100 meters above some routes, are based on elevation differences between the entrances and the mountain ridge, and do not represent direct measurements of the depth of the halls.
In its report issued on July 14, 2026, the Institute for Science and International Security identified the western entrances, power lines, support area and the likely ventilation site as visible weak points. Striking them could bury the gates and disrupt the access, power and ventilation needed to operate the facility.
But the institute noted that the entrances could be reopened if the damage were limited to external debris. The duration of disruption would increase if collapses extended inside the tunnels or if several entrances were targeted simultaneously, while the outcome would still depend on whether there are additional exits not visible in the images.
The importance of targeting power stems from what happened at Natanz in April 2021, when the attack on the electrical network caused damage inside enrichment halls and to centrifuges. Reproducing that effect at Pickaxe Mountain would depend on the design of its networks and the existence of backup power and ventilation sources.
The institute also raised sabotage and special operations among the possible options, based on the continuation of construction work and the appearance of some entrances and service points in the images.
The mountain lies within the connected security perimeter of the Natanz facility, making any approach to it and entry into its tunnels an extremely complex and risky operation, requiring precise information about guards, doors, internal passageways and means of extracting forces.
The possible outcomes of any attack range from disrupting power and ventilation and burying entrances to causing collapses that reach the halls and equipment. The effect of a strike also depends on the function of the complex and its contents at the time of the attack. If the halls are designated for centrifuge assembly, disabling them could slow the production of the equipment Iran needs to replace its losses at enrichment facilities.
If the Israeli account published by newspaper The Wall Street Journal on July 21, 2026, about moving thousands of centrifuges into the tunnels is accurate, the target’s value rises and the scale of the damage becomes tied to where the machines are stored and whether explosions or collapses can reach them.
If the project remains in the construction phase, the main effect of a strike would be delaying its completion and forcing Iran to repair the entrances and supporting facilities.
IAEA Director General Rafael Grossi had warned after the June 2025 attacks about the effects of bombing nuclear facilities on safety and the safeguards system, and called for restoring access to the sites and materials the agency had stopped monitoring. The absence of prior inspections makes it harder to assess the results of a strike, because determining what was destroyed first requires knowing what was inside the complex.
The June 2025 operation demonstrated the United States’ ability to reach Iranian nuclear sites by air and use GBU-57 bombs against hardened targets. At Pickaxe Mountain, satellite images show entrances and surface installations that could be included in the target bank, without allowing an estimate of the scale of damage that might reach the tunnels and internal halls.
The success of an attack depends on its specific objective, whether that means disrupting power and ventilation, burying entrances, halting use of the complex for a period, or destroying the equipment inside it. Disruption and damage to the external infrastructure appear to be a plausible outcome supported by the visible weak points and the US capabilities previously used, without knowing whether the site can be destroyed completely.