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

PICKAXE MOUNTAIN SITE WAS BUILT AFTER EARLIER ATTACKS ON IRAN

The new project at Pickaxe Mountain is being constructed next to Natanz, about 225km south of Tehran, Iran’s capital.

Natanz, a mix of above- and underground facilities, has been a point of international concern since its existence became known two decades ago. Repeated sabotage attacks on Natanz, including one likely carried out by Israel that destroyed a manufacturing site for centrifuges, led Iranian officials to start work on the Pickaxe Mountain site.

Protected by anti-aircraft batteries, fencing and Iran’s paramilitary Revolutionary Guard, the facility sprawls across 2.7 sq km in the country’s arid Central Plateau. It has multiple entrances visible from satellite images.

Construction of the facility at Pickaxe Mountain began in 2020, according to the Institute for Science and International Security (ISIS), following what Iranian authorities reported at the time as an explosion caused by an act of sabotage at the Natanz facility.

Iran said at the time the Natanz sabotage had caused significant damage that could slow the development of advanced uranium enrichment centrifuges.

In September that year, Iran’s then-nuclear chief, Ali Akbar Salehi, said Iran had started building “a more modern, larger and more comprehensive hall in all dimensions in the heart of the mountain near Natanz” for making advanced centrifuges.

In 2023, an Associated Press story on Pickaxe Mountain included analysis from experts at the James Martin Center for Nonproliferation Studies that suggested Iran is likely building a facility at a depth of between 80m and 100m. Digging has continued at the site in the time since, with some experts suggesting it could be even deeper underground.

Experts say the size of the construction project indicates Iran will likely be able to use the underground facility to enrich uranium as well as to build centrifuges.

Centrifuges, tube-shaped devices arranged in large cascades of dozens of machines, rapidly spin uranium gas to enrich it. Additional cascades spinning would allow Iran to quickly enrich uranium under the mountain’s protection.

Such underground facilities led the US to create the GBU-57 bomb, which can plough through at least 60m of earth before detonating, according to the American military. US officials reportedly have discussed using two such bombs in succession to ensure a site is destroyed. It is not clear that such a one-two punch would damage a facility as deep as the one at Pickaxe Mountain.