What is Pickaxe Mountain, Iran’s underground nuclear facility Trump is threatening to attack?

What Happened

US President Donald Trump threatened to strike Pickaxe Mountain, an underground Iranian nuclear facility known in Iran as Kuh-e Kolang Gaz La, located 220km south of Tehran and 2km from the Natanz enrichment site. Trump told reporters that the US military would be 'hitting that area pretty soon, and very heavily,' while acknowledging that US intelligence sees 'no activity there.' The facility, believed to be buried nearly 100 metres deep, is still under construction according to satellite imagery analysed by the Institute for Science and International Security (ISIS). Iran began building the site in 2020 after sabotage damaged the nearby Natanz facility, and it was intended for assembling advanced centrifuges. ISIS reports that the complex was not targeted in prior US-Israeli strikes in 2025 and 2026, and that recent hardening of tunnel entrances has been partially backfilled but not sealed. Trump's threats come amid a US military campaign aimed at compelling Iran to reopen the Strait of Hormuz.

Key Actors

Why It Matters

Trump’s explicit threat to directly attack a deeply buried Iranian nuclear site escalates the US–Iran standoff, linking nuclear concerns with the ongoing maritime campaign over the Strait of Hormuz. The facility’s depth and fortification challenge conventional aerial munitions, raising the possibility of ground operations—a step Trump has so far avoided. The threat signals a potential broadening of US military objectives, while Iran’s continued construction of hardened underground sites demonstrates its intent to protect the nuclear programme from external strikes, complicating diplomatic and military options.

Watch For

Monitor for actual US strikes on Pickaxe Mountain following Trump’s statement; satellite imagery revealing changes in construction, fortifications, or signs of operational activity; IAEA reports on Iran’s nuclear declarations and any mention of the facility; and potential Iranian retaliatory measures, whether through proxy forces or accelerated centrifuge assembly at other sites.