From military garrison to Mithras’ sacred site: Exclusive interview on ongoing discoveries at Türkiye’s Zerzevan Castle

Located just 13 kilometers (8.0 miles) from the town of Cinar in Diyarbakir, Zerzevan Castle is a historical site that served as a “military settlement” during the Roman Empire.

In today’s world, the castle stands as one of the key tourism destinations in the region, offering unique insights into ancient military life and religious practices.

Zerzevan Castle was primarily used as a military base in antiquity with its strategic location helping the Roman Empire’s foothold in the East. Among the site’s most notable discoveries is the world’s last known Mithras temple, offering a rare glimpse into the religious life of Roman soldiers.

Excavations have been ongoing at the site since 2014, shedding light on its fascinating history.

The castle, which is listed on UNESCO’s Tentative World Heritage List, continues to be the focus of extensive scientific research. The Ministry of Culture and Tourism, along with local authorities and Dicle University, have been pivotal in supporting excavation efforts, which started in 2014.

These excavations have revealed a wealth of ancient structures and artifacts.

So far, the excavations have uncovered 60 acres of the castle, including impressive remnants of 12-15-meter-high city walls stretching 1,200 meters in length. The site also features a 21-meter-high watchtower, a church, administrative buildings, residential areas, grain and weapon storage rooms, rock tombs, water channels, and 54 water cisterns.

Among the more unusual finds are an underground church, a shelter capable of housing 400 people, and a secret passageway.

The castle, which was used as a “military settlement” during the Roman Empire, is home to the world’s last Mithras temple.

Excavation Director Professor Aytac Coskun shared with Türkiye Today his insights regarding the progress of the excavation, underlining the accidental discovery of the Mithras sacred site in 2017.

Here are the details from our interview with Coskun:

1. What is the historical significance of Zerzevan Castle, and why is it important?

The history of Zerzevan Castle dates back 3,000 years to the Assyrian Period (882–611 B.C.). During the Persian Period (550-331 B.C.), the settlement on the King’s Road was used to ensure road security.

Findings indicate that the site was utilized during the Parthian (140–85 B.C.), Late Hellenistic, and Early Roman periods from the second century B.C. to the third century A.D. In the Roman period, the main military settlement was constructed during the Severan period (198-235 A.D.).

The walls and structures were repaired and rebuilt during the reigns of Anastasius I (491-518 A.D.) and Justinian I (527-565 A.D.), reaching their current form. The settlement was continuously used until it was conquered by Islamic armies in 639 A.D.

Recent excavations have gained significant national and international attention, turning Zerzevan Castle into a popular site for domestic and foreign tourists.

The world’s best-preserved military settlement also revealed the last known Mithras Sanctuary, a complex that marks the first sacred site of the Mithras cult on the eastern border of the Roman Empire. Zerzevan Castle and the Mithras Sanctuary are critical for the promotion and tourism of the region, Diyarbakir province, and Türkiye.

2. What is the significance of the Mithras Temple in Zerzevan Castle, and what role did it play for Roman soldiers?

Mithras is considered one of the earliest esoteric faiths in history. Temples of this mystery cult were underground, and while many existed worldwide, only a few have survived. These temples can be found within the Roman Empire, from Türkiye to England. Rituals were conducted with the utmost secrecy, and the information was shared only among adherents.

Mithras, a deity of Indo-Persian origin, was worshiped as a sun god in Persian beliefs. He symbolized light, war, justice, faith, and cosmic order. His teachings revolved around creation and cosmic control.

Exclusively male, the Mithraic religion involved seven stages of initiation, each with unique rituals. The Mithras cult peaked in the 2nd and 3rd centuries A.D. before being banned after Christianity’s adoption in the fourth century A.D.

The Mithras Sanctuary in Zerzevan Castle is notable as the first sanctuary of its kind on the eastern frontier of the empire and the last Mithras Sanctuary discovered globally.

3. What new insights about the Mithras cult have been gained from excavations in the Mithras Temple, and how did it relate to Roman soldiers?

The discovery of the Mithras Temple in Zerzevan Castle has unveiled details about initiation rituals in this secretive religion. Mithraism was an esoteric mystery cult, and the Zerzevan excavation answered numerous questions previously unknown.

It revealed one of the best preserved and perhaps oldest Mithras sanctuaries within the empire, causing a sensation both domestically and internationally.

The cult, introduced to the Roman Empire through military campaigns in the East, was widespread among soldiers, merchants, and aristocrats. Some Emperors were even adherents. Mithras worship ranged from informal shrines to formal temples like those in Rome, Ostia, London, and Zerzevan Castle.

The teachings of Mithras revolved around creation, cosmic order, and light. Initiates underwent twelve hardships and seven initiation levels, participating in secretive rituals that left no written records, with information derived only from archaeological evidence.

4. What are the most remarkable findings uncovered during excavations in Zerzevan Castle?

Zerzevan Castle, one of the world’s best-preserved garrisons, remained untouched for 1,400 years. Excavations have revealed items used by both soldiers and civilians, such as surgical tools, belt buckles, jewelry, fibulae, lamps, coins, trade tools, arrowheads, musical instruments, keys, amulets, and stamped roof tiles. The artifacts span everyday life and military activities, including a rich collection from the pagan and Christian Roman periods.

A notable discovery includes an Assyrian seal dating back 3,000 years, suggesting the site’s significant historical use. Other prominent finds include a 1,500-year-old bronze baptismal font from the sixth century A.D., now displayed at the Diyarbakir Archaeology Museum. Plans are underway to establish a dedicated museum to exhibit thousands of uncovered artworks.

5. What discoveries have been made regarding the structures surrounding Zerzevan Castle?

The garrison is encircled by 1,200-meter-long and 12 to 15-meter-high walls. The southern area houses public buildings, including 19-meter-tall watchtowers, a church, an administrative building, an arsenal, and a rock altar.

The northern section contains streets, houses, water cisterns, underground churches, and the Mithras Sanctuary. Beyond the walls are water channels, offering bowls and quarries. The Necropolis area features rock-cut and vaulted tombs.

Excavations provide insights into not just the Roman period but also the Assyrian, Persian, Parthian, and Sassanid eras. A significant underground city and numerous undiscovered structures are expected to be revealed as work progresses.

6. What impact has Zerzevan Castle’s inclusion in UNESCO World Heritage Tentative List had on excavations and preservation efforts?

In 2020, Zerzevan Castle and the Mithras Sanctuary were added to the UNESCO World Heritage Tentative List because of their unique nature. This recognition has heightened global awareness of the site, with aspirations of achieving a permanent listing soon.

The primary goal is to complete significant excavation and restoration projects. Visitors will eventually experience the captivating atmosphere of ancient Roman streets and military settlements. A Visitor Reception Center is nearing completion, and ongoing research will continue to unveil the area’s rich historical legacy.

As a result, Zerzevan Castle holds immense historical significance, offering valuable insights into ancient cultures, including the Assyrians, Romans and the Mithras cult. Its well-preserved military and sacred sites, particularly the Mithras Temple, make it an exceptional archaeological site.

The ongoing excavations and the site’s inclusion in the UNESCO World Heritage Tentative List further enhance its importance, promising exciting future discoveries that will continue to attract global attention.