What to know about Iran's Pickaxe Mountain, home to an underground nuclear site threatened by Trump

President Donald Trump has repeatedly threatened to bomb an under-construction Iranian nuclear site buried deep under a mountain, escalating tensions between the U.S. and Iran amid exchanges over the Strait of Hormuz. The site, identified as Kuh-e Kolang Gaz La, or Pickaxe Mountain, is located south of Iran's Natanz nuclear enrichment facility.

While the Natanz facility was targeted by the U.S. during a conflict in 2025, Pickaxe Mountain has remained untouched. Iran officially denied on Wednesday the existence of any secret nuclear complex at Pickaxe Mountain. Iranian foreign ministry spokesman Esmaeil Baqaei stated that Washington's focus on the site, where he insists no nuclear activity is occurring, is merely a fabricated pretext for aggression and sabotage. He asserted that Iran's nuclear activities are fully declared to the UN's atomic watchdog.

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Washington's obsessive focus on Kolang Kouh where no nuclear activity is taking place is nothing more than a fabricated pretext for aggression, destruction, and sabotage.

However, the exact nature of the activities at Pickaxe Mountain remains unclear, as the UN nuclear watchdog has never been granted access. President Trump acknowledged the possibility that Iran may have moved centrifuges to the site, potentially to depths that would challenge even the most powerful U.S. bombs. "We’ll be hitting that area... probably pretty soon. And there’s not a thing they can do about it," Trump told journalists.

The Pickaxe Mountain project, constructed next to Natanz about 225 km south of Tehran, began in 2020. This followed an explosion at the Natanz facility, which Iranian authorities attributed to sabotage. Natanz, a complex of above- and underground facilities, has been a focal point of international concern for two decades. Repeated sabotage attacks, including one suspected to be carried out by Israel, destroyed a centrifuge manufacturing site, prompting Iran to begin work on Pickaxe Mountain. The facility is protected by anti-aircraft batteries, fencing, and Iran’s Revolutionary Guard, and satellite images show multiple entrances across its 2.7 sq km area.

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We’ll be hitting that area ... probably pretty soon. And there’s not a thing they can do about it.