Furthermore, Rabana-Merquly may be the lost city of Natounia. Situated on the southwest flanks of Mt. Piramagrun in the Zagros Mountains, the stone fortress of Rabana-Merquly comprises not only the nearly four-kilometer-long fortifications but also two smaller settlements for which it is named. Because of its high position on the mountain, mapping the site was possible only with drones. Within the framework of multiple excavation campaigns conducted from 2009 and most recently between 2019 and 2022, the international team of researchers was able to study the archaeological remains on site. Structures that have survived to this day suggest a military use and include the remains of several rectangular buildings that may have served as barracks.

The researchers also found a religious complex possibly dedicated to the Zoroastrian Iranian goddess Anahita. The rock reliefs at the entrance to the fortress are of special significance, along with the geographic location of the fortification in the catchment area of the Lower Zab River, known in antiquity by its Greek name of Kapros. The researchers suspect that Rabana-Merquly may be the lost city of Natounia. Until now, the existence of the royal city known as Natounia on the Kapros, or alternatively as Natounissarokerta, has been documented only on a few coins dating from the first century BC.