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

Key Points:

• US President Donald Trump has renewed threats to strike Pickaxe Mountain, a fortified underground site near Iran’s Natanz nuclear facility, amid escalating US-Iran tensions and ongoing US strikes aimed at reopening the Strait of Hormuz.
• Pickaxe Mountain, located about 220km south of Tehran, houses a nuclear-related facility still under construction, believed to be buried nearly 100 meters underground and intended for advanced centrifuge manufacturing.
• The site has not yet become operational, according to US-based thinktank ISIS, which also notes recent efforts by Iran to harden tunnel entrances and bolster security against potential attacks.
• Experts assess that Pickaxe Mountain’s deep underground location makes it largely impervious to US bunker-buster bombs, suggesting that a ground operation or specialized deep-penetrating weapons would be required for an effective strike.
• Despite the threats, Trump acknowledged US intelligence sees no current activity at the site, and there is no indication that the US is considering deploying ground forces to attack the complex.