Hidden beneath the historic halls of Istanbul’s Hagia Sophia is a mysterious network of tunnels, corridors, and tombs. These subterranean spaces remained untouched for centuries—but now, they are set to be opened to the public for the first time.
What Lies Beneath Hagia Sophia?
The Hagia Sophia Grand Mosque—Istanbul’s iconic marvel of Byzantine architecture—boasts centuries of religious and cultural history. Adding to the monument’s mystique, a mysterious labyrinth of subterranean tunnels, vaults, and tombs lies beneath its foundation. Experts say this concealed interconnected network winds for approximately half a mile and once had many uses—including ventilation, storage, and burials—before falling into disuse beneath layers of dirt.
Türkiye‘s Ministry of Tourism and Culture recently announced plans to clean, restore, and open Hagia Sophia’s subterranean network for the first time. This process is expected to last about one year and includes the restoration of various tunnels, vaults, and corridors, as well as an especially fascinating three-room tomb. The tomb dates back to the fourth century CE, making it one of the region’s oldest architectural remnants.
“This Study Is Very Important and Valuable”
After centuries of neglect, an architectural visualization study of the underground labyrinth beneath the monument was first undertaken five years ago. Professor Hasan Firat Diker, a member of the Hagia Sophia Science Board, told Turkish media, “This study is very important and valuable in the sense that both existing places can be visited, even if only a part of them, and the findings inside are dealt with sensitivity under the supervision of the Hagia Sophia Museum and those that are revealed can shed light on the history of Istanbul.”
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Following the opening of its unseen underground, Hagia Sophia will undergo even more extensive restorations throughout the centuries-old structure. Most urgent is the preservation of its iconic dome, the underside of which is covered in mosaics, making structural intervention especially difficult.
The History of Hagia Sophia
Completed in 537 CE, Hagia Sophia was the religious and cultural center of the Byzantine Empire and, for a time, the largest Christian cathedral in the world. With its innovative pendentive dome, glittering golden mosaics, and brilliant polychrome marble, it influenced both Christian and Islamic architecture for centuries.
After the fall of Constantinople in 1453, the Ottoman Empire established control over the city, which eventually became known as Istanbul. From the 15th century to the early 20th century, Hagia Sophia served as a mosque. During this time, minarets—tall towers from which the Islamic call to prayer is projected—were added to the exterior. After being used as an interfaith museum from 1935, Hagia Sophia was controversially reclassified as a practicing mosque in 2020. It remains open to non-worshipping visitors, except for during prayer times.
