The original purpose of the mysterious subterranean vault which is present under the Naryn-Kala fortress in Derbent, Russia was not known for several decades. However, with the use of technology, the original identity of the building is now known. The study has been published in the journal Applied Sciences.
Scientists used a nuclear physics technology which is known as muon radiography. It tracks the muons that are generated by the interaction of the cosmic rays with the atmosphere of the Earth. When they pass through space, nuclear emulsion plates are used as detectors for catching the particles to develop the image of where the muons passed and the location of their absorption or deflection. Using this method to scan the subterranean structure, the team identified it to be a vast church. It could be the oldest church existing in Russia. Till now, researchers were split upon the idea if it was a church, water tank or a Zoroastrian fire temple. However it seems from the measurements, that is indeed a church.
Natalia Polukhina, a physicist from the National University of Science and Technology said that the strange building where the detectors were put resembled a cross. One of the sides is two meters longer than others. Researchers could not excavate what is present underneath the Naryn-Kala fortress as it is a UNESCO cultural heritage site. So they lowered the detectors into the depths and scanned the internal dimensions for four months.
The building measured around 11 meters high, 15 meters from north to south and 13.4 metres from east to west. The dome is present at the centre of the cruciform design.
The site was probably used as a water tank in the 17 and 18th centuries, however differences with another reservoir suggested that it was not originally used for storing water and had some other purpose.
According to the archaeologists, the building during its construction stood entirely on the surface and is on the highest point of the Naryn-Kala. Hence it does not make sense that a tank will be kept even on the highest mountain. It is understood that the building was buried after Derbent was taken over by the Sasanian Persian Empire. The area has been important strategically being a part of the trade route between Europe and the Middle East.
The scan revealed a strange build-up of muons in the western wing which indicated that architectural features which were preserved could be scanned similarly with the help of non-invasive approach. Researchers want to keep their work for producing a full-scale image of what has been buried underneath the Naryn-Kala fortress.
Journal Reference: Applied Sciences