The underground complex situated near Iran's Natanz nuclear facility has recently captured worldwide attention, particularly following remarks made by President Donald Trump on Tuesday suggesting it could become a target for military strikes. Trump claimed there is a possibility that centrifuges for uranium enrichment are housed within this enigmatic site. During a press conference at the White House, he stated, "We will likely strike that area soon. They are unable to do anything about it." In response to these threats, Iran has warned of an escalation in warfare should the United States target its nuclear facilities. The Iranian government has remained tight-lipped regarding the complex, known in Persian as 'Koh Kolang Kaz La' or 'Pickaxe Mountain.'
International Atomic Energy Agency (IAEA) inspectors have never been granted access to this site, resulting in most information being derived from satellite imagery and intelligence assessments rather than direct observation. Despite the complex appearing repeatedly in media reports over the past few years, its exact purpose remains ambiguous, contributing to its status as one of the most closely monitored sites related to Iran's nuclear activities.
What Do We Know About 'Pickaxe Mountain'?
The underground complex is located south of Tehran in Isfahan Province, approximately two kilometers (1.24 miles) from the Natanz uranium enrichment facility, which is considered one of Iran's most crucial nuclear sites. Commercial satellite images, including those published by Maxar Technologies, have revealed ongoing construction activities since 2020. These images depict new tunnel entrances, access routes, and security installations, along with large quantities of excavated rock due to the digging operations. The pace of construction appeared to accelerate following an explosion that damaged an advanced centrifuge assembly workshop at Natanz in July 2020, an incident that Iranian authorities described at the time as an act of sabotage.
Months after the explosion, Tehran announced plans to construct a new underground facility for assembling advanced centrifuges in a more secure location. Iranian officials claimed that this alternative site would be larger, more advanced, and better protected than the damaged facility. According to estimates from the Institute for Science and International Security in Washington, parts of the complex could be buried between 80 and 100 meters (330 feet) beneath the mountain. If these estimates are accurate, the complex would be deeper than many known Iranian nuclear sites, complicating any attempts to target or damage it through airstrikes.
IAEA Director General Rafael Grossi has repeatedly confirmed that inspectors have never been granted permission to access the site. In the absence of inspections, the agency cannot verify whether nuclear materials, centrifuges, or other sensitive equipment are housed within the complex.
Reports of Centrifuge Presence in the 'Pickaxe Mountain' Complex
In June 2026, the Wall Street Journal reported that Israeli intelligence assessed the likelihood of Iran transferring "thousands of components for uranium enrichment centrifuges" or other sensitive equipment to the complex during the months following a 12-day bombing campaign conducted by the United States and Israel in June 2025. When asked about this report, Trump stated on Tuesday that Iran "may have moved" centrifuges to 'Pickaxe Mountain,' adding, "But we do not have documented evidence to confirm that." Some analysts also believe that the complex could later accommodate the production or assembly of advanced centrifuges should Iran decide to restore or expand these capabilities. Iran has long asserted that its underground facilities are essential for protecting its nuclear infrastructure from sabotage and military attacks, consistently maintaining that its uranium enrichment program is intended for peaceful purposes, denying any aspirations to develop a nuclear weapon.
International inspectors and intelligence reports confirm that Iran possesses around 970 pounds (440 kilograms) of uranium enriched to levels as high as 60%, a percentage that significantly exceeds the levels needed for civilian uses and approaches the 90% threshold required for weaponization.
Discussions around the strategic significance of 'Pickaxe Mountain' have also intensified. Farzin Nadimi, a senior fellow at the Washington Institute for Near East Policy, highlighted that the site’s strategic importance lies in its ability to withstand bunker-busting bombs and its geographical proximity to the Natanz nuclear complex. He noted that damage reported in Iran's facilities at Fordow and parts of Natanz and Isfahan following the June 2025 bombing campaign has rendered the underground complex more critical than ever. He stated, "Considering Iran's security concerns, it is expected that future uranium enrichment activities, and even weapon-related activities, will be concentrated in one heavily fortified location. 'Koh Kolang Kaz La' is the most logical candidate to undertake this role."
Bunker-busting bombs used by the U.S. military are designed to penetrate layers of earth before detonating, yet even the most powerful of these weapons can only penetrate to a certain depth. The effectiveness of such bombs in destroying a complex buried at this depth under 'Pickaxe Mountain' remains a point of debate among military experts, particularly since the intricate planning of tunnels and the depth and locations of critical infrastructure have never been publicly disclosed.
Ultimately, the likelihood of disrupting the 'Pickaxe Mountain' complex remains uncertain. Unlike the Natanz or Fordow facilities, which have had their main infrastructure identified over the years, assessing the potential damage to a target entirely located within the mountain is complex. Some analysts argue that if the site were to be targeted, the military goal may not be to destroy the entire complex; instead, the more realistic military objective could be to eliminate tunnel entrances, disrupt access routes, or cripple supporting infrastructure, thereby making the operation of the facility exceedingly difficult or impossible.
Whether 'Pickaxe Mountain' ultimately becomes a site for centrifuge production, a facility for enrichment, or merely a highly fortified support complex remains unclear. However, the secrecy surrounding it, along with its location and presumed size, has transformed it into one of the most scrutinized components of Iran's nuclear program, a dossier that is likely to remain under international scrutiny for years to come.
As reported by yemenmonitor.com.
