Diyarbakır Fortress and Walls

Summary

• What: A 5.2-kilometer black basalt fortification circuit with eighty-two monumental bastions, four cardinal city gates, and integrated Hevsel Gardens forming an ancient urban defense ecosystem [1, 2].
• Where: Sur district, Diyarbakır, commanding the basalt promontory above the Tigris (Dicle) River valley [1, 2].
• Why significant: Second in length only to the Great Wall of China among historic city walls, showcasing an uninterrupted open-air epigraphic museum from Roman (349 CE) to Artuqid (1208 CE) and Ottoman eras; inscribed as a UNESCO World Heritage site in 2015 [1, 2].

Rising at the center of the Upper Tigris basin, Diyarbakır Fortress and Walls were strategically positioned as a nexus connecting Mesopotamian plains with Anatolian highlands along ancient trade and military routes [1, 2]. Constructed from hard black basalt formed by volcanic lava flows from Karacadağ, the walls encircle the city like a shield, conforming to the topography’s natural slope [1].

The Hevsel Gardens at the base of the walls, nourished by fertile alluvial deposits of the Tigris River, have sustained the city’s provisions for centuries. This human-engineered military fortification merged with the natural agricultural ecosystem to form an inseparable cultural landscape [1, 2].

Historical Context and Defensive Chronology

Early settlement traces in Diyarbakır and its surroundings date back to pre-Hellenistic Hurri-Mitanni, Assyrian, Urartian, and Median periods [2]. The ancient name Amida became the Roman Empire’s easternmost frontier fortress against the Sassanid Empire [1, 2]. The core of the surviving wall circuit was constructed and expanded during Emperor Constantius II’s reign (AD 349) [1, 2].

Conquered by Islamic forces under Iyaz b. Ganm in AH 18 (AD 639), Diyarbakır experienced its golden age under Seljuk and particularly Artuqid rule following Mervani, Hamdani, and Abbasid administrations [1, 2]. In 1085, Great Seljuk Sultan Melikshah did not view the Diyarbakır Artuqid walls merely as a defensive line but transformed their towers and gates into an open-air museum with inscriptions, double-headed eagles, bulls, lions, and sphinx carvings [1]. The fortress retained its strategic importance after the Ottoman conquest under Bıyıklı Mehmed Pasha in 1515, undergoing regular repairs [1, 2].

External and Internal Fortress Plans: Gates and Ditches

Structurally, Diyarbakır Fortress comprises two main sections: the External Fortress (Dış Kale) encircling the city and the Internal Fortress (İçkale) housing the original settlement core (Amida Mound / Virantepe) in the northeast [1]. The total perimeter of the external walls measures approximately 5,200 meters, with heights ranging from 8 to 12 meters and thicknesses between 3 to 5 meters [1]. Defensive ditches, 6 meters deep and 15 meters wide, were excavated along the outer side; on the eastern face, steep rock formations served as natural ditches descending to the Tigris [1].

The External Fortress features four monumental gates oriented toward cardinal directions [1]:

• Dağ Kapı (Mountain Gate / Harput Gate): Located northward toward Elazığ-Harput, situated between two cylindrical towers [1].
• Urfa Kapı (Rum Gate): The western gate retains Artuqid-era iron doors and carved inscriptions [1].
• Mardin Kapı (Tell Gate): The southern gate serves as the primary commercial exit to Mardin and Mesopotamian plains [1].
• Yeni Kapı (Tigris / Su Kapısı): The eastern single-arched gate overlooking the river and Hevsel Gardens [1].

The Internal Fortress functions as an independent administrative and military center, preserving remnants of the Artuqid Palace, Saint George Church, Artuqid Arch, Lion Fountain, and Ottoman armory [1].

Towers and Stone Carving Art: Ulu Beden and Yedi Kardeşler

Eighty-two monumental towers—cylindrical, polygonal, square, or semicircular in plan—adorn the walls [1]. Among these, the pinnacle of stone plastic art and inscription craftsmanship belongs to the Artuqid period [1]:

• Ulu Beden (Evli Beden) Tower: Located on the southwest section of the walls. Commissioned by Artuqid ruler el-Melikü’s-Sâlih Mahmûd in 1208 (AH 605) by architect Ca’fer b. Mahmûd al-Halebî [1]. The semicircular façade features a double-headed eagle relief, flanked by two lions and a bull [1].
• Yedi Kardeşler Tower: Constructed simultaneously by el-Melikü’s-Sâlih Mahmûd and architect Ca’fer b. Mahmûd in the same year. This cylindrical tower bears inscriptions adorned with double-headed eagles and winged lions [1].
• Nur Tower: Built during Melikshah’s reign (AD 1089) under vizier Nizam al-Mulk, distinguished by Kufic inscriptions and running horse/antelope friezes [1].
• Keçi Burcu (Goat Tower): One of the oldest and most massive polygonal bastions overlooking the Tigris Valley in the south [1].

Ecological Landscape Integrity with Hevsel Gardens

The approximately 700-hectare valley floor between the southeast base of the walls and the Tigris River is known as Hevsel Gardens [1, 2]. Irrigated by an ancient terraced system and water channels, these gardens continuously supplied vegetables, fruits, and firewood to the fortress garrison and city population for millennia [1].

Additionally, Hevsel hosts over 180 migratory bird species, fish populations, and a rich riverine ecosystem [1]. The stark contrast between the black basalt mass of the walls and the emerald greenery of Hevsel represents an unprecedented integration of defense and nature [1, 2].

UNESCO World Heritage and Conservation History

Despite partial destruction in the early 20th century (e.g., around Mountain Gate), most of Diyarbakır’s walls have survived intact to the present day [1]. Comprehensive restorations by the Ministry of Culture and Tourism and General Directorate of Foundations have revived the walls, towers, and Internal Fortress [1].

In 2015, “Diyarbakır Fortress and Hevsel Gardens Cultural Landscape” was officially inscribed on UNESCO’s World Heritage List at a meeting in Bonn, Germany [1].

Frequently Asked Questions

• When were Diyarbakır Fortress and Walls constructed?
  The initial wall circuit was expanded during Emperor Constantius II’s reign (AD 349); its current form emerged through additions during Seljuk, Artuqid, and Ottoman periods [1, 2].
• What stone was used in the walls’ construction?
  Hard, porous black basalt cut stones quarried from Karacadağ’s volcanic terrain were employed [1].
• How many towers and gates does the fortress have?
  Eighty-two monumental towers and four main city gates (Mountain Gate, Urfa Gate, Mardin Gate, New Gate) are present [1].
• Who commissioned Ulu Beden and Yedi Kardeşler Towers?
  Artuqid ruler el-Melikü’s-Sâlih Mahmûd commissioned them in 1208 from architect Ca’fer b. Mahmûd al-Halebî [1].
• When were Diyarbakır Walls inscribed on UNESCO’s list?
  In 2015, alongside Hevsel Gardens, as a cultural landscape area [1].

References

• [1] DIYARBAKIR (Architecture) - TDV İslâm Ansiklopedisi (Prof. Dr. Abdüsselâm Uluçam, Vol. 9, pp. 464–469), https://islamansiklopedisi.org.tr/diyarbakir#2-mimari
• [2] DIYARBAKIR (History) - TDV İslâm Ansiklopedisi (Prof. Dr. Şevki Nezihi Aykut, Vol. 9, pp. 458–464), https://islamansiklopedisi.org.tr/diyarbakir#1-tarih