Top image: Aerial view of the Mithras temple at Diyarbakır's Zerzevan Castle.

Excavations at Zerzevan Castle in the Çınar district of Diyarbakır, southeastern Turkey, have unearthed an area where participants of secret rituals resided in a 1,900-year-old underground temple dedicated to the Mithras religion! 

Located near the Demirölçek neighborhood, approximately 13 kilometers (8 miles) from the district, Zerzevan Castle served as a "military settlement" during the Roman Empire and is a significant tourist attraction for the region. 

Excavation work began in 2014, supported by the Ministry of Culture and Tourism, the governorship, Diyarbakır Museum, the Çınar District Governorate, and Dicle University. These efforts have continued at the historic site, which is on the UNESCO World Heritage (Tentative) List, reports Daily Sabah.

A Military Garrison, an Underground Temple and a Mystical Cult 

To date, excavations have revealed remnants of walls 12-15 meters (39-49 feet) high and 1,200 meters (3937 feet) long, a watchtower and defense tower 21 meters (68.89 feet) high, a church, an administrative building, residences, grain and weapon depots, rock tombs, water channels, 54 water cisterns, an underground church, an underground shelter that can accommodate 400 people, secret passages, and an underground temple linked to the Mithras religion.  

This religion, a mystery cult centered around the worship of Mithras, a deity associated with the sun, light, and justice, lost its prominence after Christianity was adopted in the 4th century AD. Mithraism emerged in the Roman Empire during the first century AD and reached its height of popularity in the 2nd and 3rd centuries.  

The religion primarily appealed to soldiers, traders, and members of the Roman elite, who were drawn to its emphasis on discipline, loyalty, and brotherhood. Mithras, often depicted slaying a bull in what is known as the tauroctony, symbolized the triumph of good over evil and light over darkness. Mithraic rituals were shrouded in secrecy and conducted in underground temples called mithraea, designed to mimic caves.

Mithras and the Bull: This fresco from the?Mithraeum?at Marino, Italy (third century) shows the?tauroctony?and the celestial lining of Mithras' cape.

This year's excavations have uncovered the area where guests who participated in secret religious ceremonies and rituals at the Mithras temple stayed. Excavation director Aytaç Coşkun explained that they have been excavating Zerzevan Castle for ten years, focusing this year on the Mithras sanctuary, the most significant part of the castle. 

Coşkun mentioned that the Mithras sanctuary was discovered by chance in 2017, and they were unaware of any structures related to the Mithras belief when they began excavations in the area. Previous finds included a temple, an underground structure, and a monumental entrance related to the Mithras belief, with the Mithras sanctuary being the castle's most critical structure. 

Through these excavations, they have found information about this mysterious belief system, which lacks written records, and shared it with the scientific community. He added that they aim to complete work in the accommodation area by the end of the year, reported Turkiye Today. 

"We are excited to find the places where Mithras adherents, who came from different parts of the Roman Empire to participate in secret ceremonies and rituals, stayed in the sanctuary. Visitors from every country, especially from the U.S., U.K., Switzerland, Japan and Russia, come to see the Mithras sanctuary. Visitors come here to see the area where the oldest esoteric belief within the borders of the Roman Empire was experienced. This is very important for the region's and the country's tourism," he explained. 

Zerzevan Castle: A Strategic Frontier 

Zerzevan Castle, a military settlement along an ancient road, is situated on a 124-meter-high rocky hill, occupying a strategic location between Amida and Dara. Overlooking the entire valley and controlling a vast area due to its position on an ancient trade route, the castle was the scene of significant conflicts between the Romans and Sasanians. 

The settlement dates back to the Assyrian period 611-882 BC, with its primary military structures built during the Roman period in the 3rd century AD. It was continuously used until its capture by Islamic armies in 639 AD. The settlement's walls and structures were repaired, and some rebuilt during the reigns of Anastasios I (491-518 AD) and Justinianos I (527-565 AD). 

The Mithras temple, located north of Zerzevan Castle, was carved into the main rock underground along the eastern wall of the structure. It features columns carved into the main rock, a large central niche, and two smaller side niches.