Archive · 10 Sep 2026
Construction Surges at Iran’s Pickaxe Nuclear Site Amid War
Satellite pictures show Iran doing much more building at a site beneath Pickaxe Mountain.
The site is near Iran’s Natanz nuclear complex, about 140 miles south of Tehran.
Experts from the Center for Strategic and International Studies studied pictures from six years.
They saw stronger tunnel entrances, paved roads, and earth being cleared away.
The experts said the facility probably cannot enrich uranium yet, if that is its purpose.
It might instead be used to assemble centrifuges or protect other nuclear work.
Israeli intelligence has suggested Iran may move centrifuges there, but the analysts could not confirm that claim.
President Donald Trump has threatened to attack the site.
The United States is also developing ways to reach facilities buried very deep underground.
CSIS analysts found a clear 2026 construction surge at Iran’s suspected underground Pickaxe Mountain nuclear site after reviewing six years of satellite imagery.
Work included reinforcing tunnel entrances, paving internal roads, strengthening access areas, and clearing excavation debris.
CSIS said continuous construction suggested the facility was not yet capable of enrichment, if enrichment is its intended purpose.
The site could become a centrifuge assembly facility, an enrichment plant, or a shelter for other nuclear-related activities.
Donald Trump has threatened to strike Pickaxe Mountain, while the United States develops capabilities for deeply buried targets.
- Who
- Iran is developing the Pickaxe Mountain site; the Center for Strategic and International Studies analyzed satellite imagery; the United States, Israel and international inspectors are monitoring related concerns.
- What
- Satellite imagery shows increased construction at a suspected underground Iranian nuclear facility.
- When
- The surge was identified in 2026 after analysts reviewed imagery covering six years; the reports also describe intensified US-Iran fighting after a month of relative calm.
- Where
- Pickaxe Mountain, or Kuh-e Kolang Gaz La, about 2 kilometers south of Iran’s Natanz nuclear facility and roughly 140 miles south of Tehran.
- Why
- The site may be intended to support, protect or expand Iran’s future nuclear activities, but its exact purpose has not been established.
Analysts’ Assessment
Security Concerns and Strike Planning
Current capability
Analysts’ Assessment
CSIS said the continuing construction indicated Pickaxe Mountain was probably not yet capable of enrichment, if that is its intended purpose.
Security Concerns and Strike Planning
Israeli intelligence has suggested Iran may be moving centrifuges and centrifuge components into the site for uranium-enrichment activities; the analysts said they could neither confirm nor disprove that claim.
Potential purpose
Analysts’ Assessment
The facility could be used for centrifuge assembly, uranium enrichment or other nuclear-related work, but the available imagery does not establish which purpose applies.
Security Concerns and Strike Planning
US and Israeli security concerns focus on the possibility that the deeply buried site could protect important Iranian nuclear activities from attack.
Feasibility of an attack
Analysts’ Assessment
CSIS analysts said the granite mountain would be difficult to penetrate, even with the heaviest non-nuclear US bombs, and there were doubts that existing weapons could destroy the facility.
Security Concerns and Strike Planning
Trump has repeatedly threatened to strike Pickaxe Mountain, the US military has maintained operational plans, and the United States is developing a next-generation penetrator for deeper underground targets.
- Site
- Pickaxe Mountain is a deeply buried tunnel complex beneath a granite mountain near Natanz.
- Analysis
- The Center for Strategic and International Studies reviewed six years of satellite imagery, with the latest imagery dated August 9.
- Construction
- Observed work included hardening tunnel portals, paving roads, reinforcing access areas and removing excavation spoil.
- Possible purposes
- Analysts identified centrifuge assembly, uranium enrichment and sheltering other nuclear-related activities as possible uses.
- Enrichment capability
- CSIS said continuous construction suggested the facility was not yet capable of enrichment work, if that is its intended purpose.
- International access
- The International Atomic Energy Agency has requested information and access, but the reports say Iran has not responded or facilitated access.
- US response
- Donald Trump has threatened to strike the site, while the US military maintains operational plans and is developing deeper-penetrating weapons.
