Updated: Apr 4, 2021
The site is located near Khomeyni Shahr, 28 kilometers North West of Isfahan City Center, Iran.
Construction began circa 2005 with the excavation of two tunnels inside the mountains, 400 meters below crest level.
It is only by 2008-2009 that ventilation shafts appeared indicating that the site needs fresh air circulation beyond the temporary ventilation during the underground excavation works.
Analyzing the initial spoils it can be roughly estimated that a volume of 500,000 cubic meters was excavated for the two tunnels and underground facilities. It is not clear if those tunnels are interconnected and sharing one common underground facility.
By 2011, the area was further developed, three concrete batch plants started to operate on-site and two security perimeters added.
Between 2011 and 2019, no major excavation could be reported, however, arched formwork and concrete production were still in progress probably indicating that construction work took place underground.
Around August 2019, at each tunnel entrance, 10 meters high platforms with access ramps were built with fill and subbase. By the end of 2019, those elevated platforms were reinforced with rebars and concrete in their centroid points indicating the requirement to sustain high forces and loads.
Similar platforms at tunnel entrance or pads were revealed by The Intel Lab at Masjed Soleyman Airbase on January 16th, 2021. The same concept can be found at Sangnam-ni Missile Base in North Korea which is likely one of many contributions to the Iranian Ballistic Missile Program.
As for today, persistent intelligence using Very High-Resolution 0.5m SAR imagery from Capella Space indicates that works inside the mountains are still ongoing and the site is not operational yet.