The Hagia Sophia, a historic landmark in Istanbul, has unveiled a hidden network of tunnels dating back around 1,600 years. This discovery, made during a restoration project, adds a fascinating layer to the monument's rich history. The tunnels, along with a hypogeum (an underground burial complex), were found beneath the structure, shedding light on the intricate underground world beneath the iconic building.
The restoration campaign, led by Turkey's Culture and Tourism Minister Mehmet Nuri Ersoy, involves a comprehensive process. It includes scanning, modeling, and meticulous material analysis across the site. During the cleaning operations, seven tunnel lines were documented, and a significant 1,068 tons of soil fill were removed. Additionally, a separate underground burial area yielded another 102 tons of debris.
This isn't the first time the Hagia Sophia's subterranean secrets have come to light. However, the latest findings are notable for their concrete documentation. Tunnel "lines" have been named, the amount of removed spoil is measured, and visual records are now publicly accessible. Professor Hasan Fırat Diker, an expert in the field, emphasizes the practical functions of these tunnel and culvert systems, which are crucial for ventilation and water management.
The restoration work is not limited to the underground. Above ground, major efforts are underway, including scaffolding, façade cleaning, and structural checks. These measures aim to preserve the building for centuries, ensuring its long-term safety. Minister Ersoy stresses the importance of scientific assessments and contemporary restoration requirements, a critical aspect given the earlier use of inappropriate materials like cement-based plasters.
The timing of the restoration also reflects a broader concern: Istanbul's earthquake risk. Engineers are carefully assessing vulnerable structural points while maintaining the building's integrity. The restoration's focus on the underground, including load paths, drainage, and humidity control, is a testament to the building's historical reliance on these systems.
Hagia Sophia's underground world is part of a larger context. Istanbul, a city built with water below its feet, features cisterns, conduits, and storage systems that once supplied palaces, churches, and neighborhoods. The present Hagia Sophia, constructed in 532-537 AD under Emperor Justinian I, has a history of repairs following earthquakes. This architectural narrative highlights the importance of hidden infrastructure for the building's survival.
Nearby, the Basilica Cistern stands as a public example of Byzantine Istanbul's water management. Tunnel-like maintenance spaces around major monuments are plausible due to such ancient systems. Researchers can now better understand drainage, humidity, and maintenance practices during different eras, including the Byzantine, Middle Byzantine, and Ottoman periods, thanks to the newly documented tunnel lines.
