International experts are expressing significant concern regarding Iran's nuclear activities at a previously undisclosed underground site, identified as Pickaxe Mountain. The facility, located in Iran's Zagros Mountains, has reportedly seen ongoing construction, according to analysis of satellite imagery.

Compounding these concerns is the International Atomic Energy Agency's (IAEA) lack of access to the site. IAEA inspectors have not been permitted to visit the facility, raising questions about the transparency of Iran's nuclear program and adherence to international safeguards.

The continued development at Pickaxe Mountain, coupled with restricted access for oversight bodies, has intensified scrutiny from experts monitoring Iran's nuclear trajectory. The implications of such undeclared and uninspected nuclear work remain a subject of international deliberation and concern.