Why Trump Is Targeting Iran's 'Pickaxe Mountain'

A mysterious underground complex near Iran’s Natanz nuclear facility has drawn worldwide attention after US President Donald Trump on Tuesday (21 July) proposed it as a target for military strikes, whilst claiming that a uranium enrichment facility may exist at the site.

“We will most likely strike that area in the near future. There is nothing they can do to stop it,” Trump told reporters at the White House.

Iran has threatened to expand the war if the US attacks its nuclear facilities.

Tehran has released almost no information about the complex buried underground, known in Farsi as Kuh-e Kolang Gaz La, or Pickaxe Mountain.

Inspectors from the International Atomic Energy Agency (IAEA) have never been granted access to the site, and most of the available information comes from satellite imagery and intelligence assessments rather than direct observation.

Although the location has repeatedly appeared in various reports in recent years, its purpose remains unclear. This ambiguity has made it one of the most closely watched sites related to Iran’s nuclear activities.

What is at Pickaxe Mountain?

The underground complex is located south of Tehran, in Iran’s Isfahan province. It was dug into a mountain and lies roughly two kilometres from the Natanz uranium enrichment plant, one of Iran’s most important nuclear facilities.

Commercial satellite imagery, including images published by Maxar Technologies, shows construction activity continuing since 2020.

The imagery reveals new tunnel entrances, access roads, security installations and large piles of excavated rock.

Construction activity appeared to accelerate after an explosion damaged Iran’s advanced centrifuge assembly workshop at Natanz in July 2020. Iranian authorities described the explosion as an act of sabotage.

Several months later, Tehran announced plans to build a new underground facility where advanced centrifuge equipment could be assembled in a safer location. Officials said the replacement site would be larger, more advanced and better protected than the facility that had been damaged.

The Washington-based Institute for Science and International Security has estimated that parts of the facility may be buried 80 to 100 metres beneath the mountain.

If those estimates are accurate, the complex would be deeper than many of Iran’s known nuclear sites and far more difficult to destroy through air strikes.

IAEA Director General Rafael Grossi has repeatedly stated that the agency’s inspectors have never been given permission to enter the site. Without inspections, the agency cannot verify whether nuclear material, centrifuges or other sensitive equipment are present there.

Reports of uranium enrichment machines at the Pickaxe complex

In June 2026, The Wall Street Journal reported that Israel’s intelligence services had assessed that Iran may have moved “thousands of uranium enrichment centrifuge machines” or other sensitive equipment to the complex in the months following the 12-day air campaign by the US and Israel in June 2025.

Responding to questions about the report, Trump said on Tuesday (21 July) that Iran “may have” moved centrifuges to Pickaxe Mountain, but “we have no record of that.”

Some analysts also believe the complex could eventually support the production or assembly of advanced centrifuges should Iran decide to restore or expand its nuclear capabilities.

Iran has consistently maintained that underground facilities are necessary to protect its nuclear infrastructure from sabotage and military attacks. Tehran has always claimed its enrichment activities are for peaceful purposes and has denied any effort to produce weapons.

International inspectors and intelligence reports confirm that Iran holds around 440 kg of uranium enriched to 60 per cent purity, far above the level required for civilian purposes and approaching the 90 per cent needed to produce weapons.

A bomb-proof bunker?

Farzin Nadimi, a senior researcher at the Washington Institute for Near East Policy, told DW that Pickaxe Mountain’s strategic importance “lies in its resistance to bunker-busting bombs as well as its proximity to the Natanz nuclear complex.”

Nadimi argued that the reported damage to Iran’s facilities at Fordo, parts of Natanz and Isfahan after the bombing campaign in June 2025 has made the existence of the underground complex more important than ever.

“Given Iran’s security considerations, it can be expected that future enrichment activities, even weapons-related ones, will ultimately be concentrated in one heavily protected location,” he said. “Pickaxe Mountain is the most logical candidate for that role.”

Bunker-buster bombs used by the US military are designed to penetrate layers of earth before detonating, but even the most powerful weapons can only reach a certain depth.

Whether such bombs could destroy the complex buried within Pickaxe Mountain remains a matter of debate among military experts. The exact layout of the tunnels, their depth, and the location of critical infrastructure inside have never been made public.

The possibility of disabling the Pickaxe facility

Unlike Natanz or Fordo, where the main facilities have been identified for years, it is difficult to assess damage to a target located inside a mountain.

Some analysts argue that if the site were targeted, the aim might not be to destroy the entire complex. A more realistic military objective would be to collapse tunnel entrances, damage access routes or disable supporting infrastructure, making the facility difficult or impossible to operate.

It remains unclear whether Pickaxe Mountain will ultimately become a centrifuge production site, an enrichment facility, or merely a heavily guarded support complex.

Its secrecy, location and apparent scale have made it one of the most closely monitored elements of Iran’s nuclear programme. The project will most likely remain under intense international scrutiny for years to come.