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February 28, 2026
1,600-Year-Old Underground Tunnels Discovered Under Hagia Sophia During Restoration
Seven underground tunnels dating back approximately 1,600 years have been discovered under Hagia Sophia during ongoing restoration works, offering a rare glimpse into the monument's early Byzantine period infrastructure, while Minister of Culture and Tourism Mehmet Nuri Ersoy confirmed that preservation works in both Hagia Sophia and the Blue Mosque are progressing under strict scientific supervision.
TL;DR
- Seven underground tunnels, dating back approximately 1,600 years to the Early Byzantine period, have been discovered beneath Hagia Sophia.
- Restoration works at Hagia Sophia are progressing under strict scientific supervision, with academic advisory boards and specialized teams involved.
- Scaffolding covers large areas of Hagia Sophia's exterior, and material analyses have led to the removal of older cement-based mortars and subsequent cleaning and desalination treatments.
- Laboratory research has identified construction materials from Early Byzantine, Middle Byzantine, and Ottoman phases, with custom-made historical bricks now being used in restoration.
- Georadar surveys and digital modeling are being conducted for structural stability assessment and reinforcement planning.
- Intensified works on Hagia Sophia's dome and minarets include controlled dismantling, documentation, and reinstatement of the northeast minaret, along with restoration of structural elements, balcony floors, railings, and the copper finial.
- A large scaffolding system has been installed inside Hagia Sophia's dome, and temporary steel roof systems are protecting interior mosaics.
- Scientific teams have undertaken cleaning and documentation of three underground chambers connected to a tunnel network in the western garden and northern facade.
- Over 1,000 tons of soil were removed from the tunnels in 2025, and an additional 102 tons from an underground tomb complex in the Vezir Garden area.
- The restoration of the Blue Mosque (Sultanahmet Mosque) is complete, described as the most comprehensive preservation in its over 400-year history.
- Blue Mosque restoration included structural repairs on minarets, renewal of finishes and railings, renewal of lead roofing material, and restoration of gilded finials.
- Internal platform systems played a crucial role in protecting mosaics and enabling swift intervention during structural reinforcement works at the Blue Mosque.
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