"We're seeing a little activity at Pickaxe Mountain. I would advise Iran not to play games, because if they do, we're going to hit them very hard," President Donald Trump stated at a Republican conference on 9/9.

Pickaxe Mountain, also known as Kuh-e Kolang Gaz La, is located in the Zagros range, approximately 220 km south of Tehran and about two km from the Natanz nuclear complex. President Trump has repeatedly warned of a potential strike on this site since at least mid-july.

Satellite imagery from july shows construction activity at Pickaxe. *Graphic: CSIS*

Trump's threat comes as construction activity at the Pickaxe mountain complex appears to have increased significantly. The latest commercial satellite photos reveal Iran has accelerated construction, including roads and reinforced tunnel entrances, with signs of activity in internal areas. However, this imagery cannot confirm whether Iran is enriching uranium or producing nuclear warheads there.

The US-based Center for Strategic and International Studies (CSIS) stated that it cannot confirm whether centrifuges have been moved into the tunnels at Pickaxe Mountain. CSIS assesses that the facility might not yet be capable of uranium enrichment.

Locations of the entrances to the Pickaxe complex and the Natanz nuclear facility. *Graphic: CSIS*

The Wall Street Journal reported in 7/2025, citing informed sources, that Iran might have moved thousands of centrifuges into the tunnel network under Pickaxe Mountain since fall 2024. This action does not necessarily mean Iran has commenced uranium enrichment operations; it could be intended to reduce the risk of losing vital equipment during conflicts. Iranian officials and the International Atomic Energy Agency (IAEA) did not comment on this information at the time.

Iran has constructed two independent underground tunnel systems beneath the mountain, with the first project starting in 2007 and the second taking shape from 2020. The Pickaxe complex is believed to replace an Iranian centrifuge assembly facility that was severely damaged in a suspected sabotage explosion in 2020.

Western experts acknowledge that any airstrike targeting the site would face numerous challenges. The underground tunnel network at Pickaxe Mountain lies approximately 600 m deep beneath solid granite, rendering it an "impenetrable nuclear fortress" against all bombs currently in the US military's arsenal.

Satellite image of the Pickaxe complex near the Natanz nuclear facility earlier this year. *Photo: CSIS*

The US and Israel have monitored Pickaxe Mountain for years but have gathered limited information about activities at the site. Iran does not permit IAEA inspectors access to Pickaxe Mountain and has not provided information about activities there. IAEA Director General Rafael Grossi previously stated that Iran had announced its intention to conduct nuclear activities at this location in 2021.

Thanh Danh (According to Reuters)