Iran Strengthens Underground Nuclear Complex in Response to Heightened Tensions

Fri Feb 13 2026 03:11:28 GMT+0200 (Eastern European Standard Time)

Satellite imagery reveals that Iran is reinforcing an underground facility near its nuclear site amid rising tensions with the U.S. over its nuclear program. The construction is viewed as a precaution against potential military action.

Iran has been observed fortifying an underground complex near its nuclear facility using new satellite images. The activities coincide with increased tensions with the U.S., as talks regarding Iran's nuclear program continue. Experts suggest this facility might be crucial for protecting uranium enrichment activities. Both the Natanz nuclear site and the Isfahan nuclear complex have also seen repairs and enhancements, leading to concerns over Iran's nuclear aspirations.

Iran has been fortifying an underground complex near one of its nuclear facilities, according to analysis of new satellite images. This activity comes at a time of heightened tensions as talks between Iranian and US officials continue, with President Donald Trump threatening fresh military actions against Iran if it does not agree to a new deal on its nuclear programme.

The photos, first analysed by the Institute for Science and International Security (ISIS), show tunnel entrances being strengthened at Mount Kolang Gaz La, also known as Pickaxe Mountain. Experts say this facility may be designed to protect Iran's uranium enrichment activities or key equipment, but its exact purpose—and whether it is operational—remains unclear.

Iran insists its nuclear programme is entirely peaceful and denies it is seeking to develop nuclear weapons. However, Trump stated that Iran was as little as a month away from having a nuclear weapon in June 2025, prompting strikes on underground nuclear sites where centrifuges were producing highly enriched uranium during a 12-day war between Israel and Iran last year.

While Pickaxe Mountain was not one of the locations attacked, the Natanz facility, located about 2 km north, was hit. A recent satellite image from February 10 shows fresh concrete laid over one of the entrances.

Experts at ISIS have noted that these changes may be intended to strengthen the tunnel entrances against potential airstrikes, suggesting that the ongoing presence of heavy construction machinery indicates the facility is not yet operational.

Additionally, satellite imagery indicates that repair work and defensive strengthening are happening at both the Natanz and Isfahan nuclear sites. Earth has been used to seal entrances at Isfahan's tunnel complex, a method designed to dampen impacts from potential airstrikes and protect against land-based assaults.

According to those familiar with the situation, Iran appears to be preparing for possible strikes by bolstering its nuclear sites. The international community remains alert to Iran's nuclear capabilities and potential developments.