A mysterious underground complex near Iran’s Natanz nuclear facility is drawing global attention after US President Donald Trump suggested Tuesday it could become the target of a military strike, with Trump claiming there may be uranium centrifuges located at the site.
“We’ll be hitting that area very probably pretty soon. And there’s not a thing they can do about it,” Trump said in remarks to reporters at the White House.
Iran has threatened to “expand” the war if the US targets nuclear facilities.
Tehran has released almost no information about the complex burrowed under what is known in Farsi as “Kuh-e Kolang Gaz La,” or Pickaxe Mountain.
Inspectors from the International Atomic Energy Agency (IAEA) have never been allowed inside, and much of what is known comes from satellite imagery and intelligence assessments rather than direct observation.
Although the site has surfaced repeatedly in reports over the past few years, its purpose remains unclear. That uncertainty has made it one of the most closely watched locations linked to Iran’s nuclear activities.
What do we know about Pickaxe Mountain?
The underground complex is located south of Tehran in Iran’s Isfahan province, excavated inside a mountain about 2 kilometers (1.24 miles) from the Natanz uranium enrichment plant, one of the country’s most important nuclear facilities.
Commercial satellite images, including those published by Maxar Technologies, have shown continuous construction since 2020.
They show new tunnel entrances, access roads, security installations and large amounts of excavated rock.
Construction appears to have accelerated after an explosion damaged Iran’s advanced centrifuge assembly workshop at Natanz in July 2020. Iranian authorities described the blast as an act of sabotage.
Months later, Tehran announced plans for a new underground facility where advanced centrifuges could be assembled in a more secure location. Officials said the replacement site would be larger, more advanced and better protected than the one that had been damaged.
The Washington-based Institute for Science and International Security estimates that parts of the facility may be buried 80 to 100 meters (330 feet) beneath the mountain.
If accurate, the complex would be deeper than many of Iran’s known nuclear sites and considerably more difficult to damage with an airstrike.
IAEA Director General Rafael Grossi has repeatedly said agency inspectors have never been granted access to the site. Without inspections, the agency cannot verify whether nuclear material, centrifuges or other sensitive equipment are present.
Reports of centrifuges in Pickaxe complex
In June 2026, The Wall Street Journal reported that Israeli intelligence has assessed that Iran may have transferred “thousands of uranium-enrichment centrifuges” components or other sensitive equipment to the complex in the months following the 12-day bombing campaign by US and Israel in June 2025.
Trump was asked about the report on Tuesday, and said that Iran “may have” moved the centrifuges to Pickaxe Mountain, but “we don’t have it on record.”
Some analysts also believe the complex could eventually support the production or assembly of advanced centrifuges if Iran decides to restore or expand those capabilities.
Iran has consistently argued that underground facilities are necessary to protect its nuclear infrastructure from sabotage and military attack. Tehran has always claimed its nuclear enrichment is for peaceful purposes, and has denied trying to produce a weapon.
International inspectors and intelligence reports confirm that Iran possesses approximately 970 pounds (440 kilograms) of uranium enriched up to 60% purity, which is far above the level needed for civilian purposes and approaches the 90% needed to produce weapons.
Bomb-proof bunker?
Farzin Nadimi, a senior fellow at the Washington Institute for Near East Policy, told DW that the strategic importance of Pickaxe Mountain “lies in its resistance to bunker-buster bombs and its proximity to the Natanz nuclear complex.”
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
Nadimi argues that the reported damage to Iran’s facilities at Fordo and parts of Natanz and Isfahan after the June 2025 bombing campaign has made the underground complex more important than before.
“Given Iran’s security considerations, one should expect that future uranium enrichment and even weapon-related activities could eventually be concentrated in a single, heavily protected location,” he said. “Pickaxe Mountain is the most logical candidate for that role.”
The bunker-buster bombs used by the US military are designed to penetrate terrain before detonating, but even the most powerful of those weapons can only reach a certain depth.
Whether they could destroy a complex buried as deeply as Pickaxe Mountain remains a matter of debate among military experts. The exact layout of the tunnels, their depth and the location of any critical infrastructure have never been made public.
What are the chances of crippling Pickaxe facility?
Unlike Natanz or Fordo, where key facilities have been identified over the years, it is difficult to assess damage to a target located inside a mountain.
Some analysts argue that if the site were ever targeted the objective might not be to destroy the entire complex. A more realistic military goal could be to collapse tunnel entrances, damage access routes or disable supporting infrastructure, making the facility difficult or impossible to operate.
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
Whether Pickaxe Mountain eventually becomes a centrifuge production site, an enrichment facility or simply a heavily protected support complex remains unclear.
Its secrecy, location and apparent scale have turned it into one of the most closely watched pieces of Iran’s nuclear program, which is likely to remain under international scrutiny for years to come.
Edited by: Wesley Rahn
About The Author
