Satellite images show surge in construction at Iran’s Pickaxe Mountain nuclear site

A suspected Iranian nuclear facility buried deep under granite near the Natanz complex has seen a clear surge in construction activity this year amid the ongoing conflict with the United States, according to a new satellite imagery analysis by the Center for Strategic and International Studies (CSIS).

The Pickaxe Mountain site, located roughly 140 miles south of Tehran, has long drawn scrutiny from intelligence agencies as a potential safe haven for Iran’s nuclear program.

Analysts who examined six years of imagery reported that work at the site has shifted from active excavation toward probable internal construction and continued exterior reinforcement.

“There has been a clear surge in construction activity” in 2026, the CSIS team found in findings shared with CNN, including more road activity than ever before, raising and hardening of tunnel portal accesses, paving of the internal road network, reinforcement around access areas, and the flattening and removal of excavated dirt.

The underground facility is “likely” designed as a safe haven for Iran’s nuclear efforts, CSIS analysts said.

Possible purposes include a centrifuge assembly facility, an enrichment site, or a protected location for other nuclear weapons-relevant work such as uranium metal conversion.

‘Israeli’ intelligence has previously suggested Iran may be moving centrifuges there as part of enrichment efforts.

However, the CSIS report cautioned that continuous construction indicates the site “is not yet capable of enrichment work, if that is the intended purpose.”

US President Donald Trump has repeatedly threatened to strike the site. “We may hit Pickaxe very soon,” he told reporters last week, adding that “we know everybody that’s moving” there.
Earlier, he said the United States would hit the area “pretty soon, and very heavily,” and warned Iranians to “be ready.”
The facility was not targeted in earlier US and ‘Israeli’ strikes during the conflict, which has lasted about six months.

The granite mountain poses a major challenge even for the Pentagon’s heaviest non-nuclear bombs.

The site is estimated to lie more than 100 meters (about 330 feet) underground in hard rock, deeper and tougher than facilities struck previously.

A top US general previously noted that deeply buried sites like Isfahan had only their entrances targeted because existing bunker-busters, including the Massive Ordnance Penetrator, were not believed capable of fully destroying them.

There are signs the US is developing ways to strike such hardened targets, according to CNN.

Four days before the launch of Operation Epic Fury, a Defense Threat Reduction Agency program manager signed an emergency $1.2 million contract to repair a unique subterranean test facility at White Sands Missile Range in New Mexico for a “live-fire test designed to validate classified capabilities against rapidly emerging threats.”

The memo cited a “time-sensitive national security directive,” and sources familiar with the matter linked the plans to the Iran conflict and the need to target Iran’s deepest underground facilities.

Satellite imagery shows excavation work began at the remote White Sands test site between February 16 and 18, aligning with the contract timeline.

The US military is also advancing a “next generation penetrator” bomb to succeed the current Massive Ordnance Penetrator, with a prototype contract awarded in September 2025.

The military maintains operational plans for strikes against Pickaxe involving some of its largest bombs, though it remains unclear whether they can penetrate deeply enough.

A source familiar with the matter told CNN said the Defense Department recently held a “planning sprint” on decisive strikes against underground facilities.

Pickaxe was part of a target package under consideration earlier this summer when Trump threatened escalation.

Meanwhile, construction at the Iranian site continues, with analysts noting the transition toward internal buildout and hardening that could further complicate any potential attack.