CORFU, Greece - The UNESCO Chair on Threats to Cultural Heritage and Cultural Heritage-Related Activities at the Ionian University is calling for greater transparency, international scientific cooperation and strengthened heritage safeguards concerning major restoration and structural consolidation works at Hagia Sophia.
In a communication dated 12 October 2026 addressed to the Director of UNESCO’s World Heritage Centre, the Chair raises concerns about publicly reported interventions at the monument, a component of the Historic Areas of Istanbul World Heritage property. It asks the Centre to verify the information with the Turkish authorities through the procedures established under the World Heritage Convention.
The intervention is grounded in paragraphs 172 and 174 of the Operational Guidelines for the Implementation of the World Heritage Convention. Paragraph 172 calls on States Parties to inform the World Heritage Committee, through the Secretariat, of planned major restorations or new constructions that may affect a property’s Outstanding Universal Value, before decisions that would be difficult to reverse are taken. Paragraph 174 provides that, when the Secretariat receives information from sources other than the State Party concerned about serious deterioration of a property or failure to undertake necessary corrective measures, it will, as far as possible, verify the source and content in consultation with that State Party and request its comments. Within this framework, the Chair brings the information to the World Heritage Centre’s attention for verification, without prejudging the outcome.
The communication draws attention to reports of extensive works on the main dome and eastern half-dome, conservation of mosaics and marble decoration, the use of heavy machinery inside the building, and investigations of underground structures beneath the historic complex. It seeks clarification of the measures protecting the monument’s structural fabric, historic floors, archaeological remains and successive cultural layers.
The Chair reports that it has not identified publicly available Heritage Impact Assessments, complete technical documentation or an ICOMOS Technical Review relating to the current restoration programme in the World Heritage Centre’s public record. This observation is presented as a matter requiring verification, rather than a conclusion that such documentation does not exist.
The Chair’s principal requests include:
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Prompt submission of complete technical documentation and Heritage Impact Assessments for the restoration and consolidation works, together with detailed information on underground interventions and their intended uses.
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Open access for experts and scholars to the scientific data and scanned documentation collected at the monument.
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Implementation of the recommendations arising from UNESCO and ICOMOS visits and monitoring missions in 2020, 2021 and 2024.
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Establishment of an international multidisciplinary scientific committee by expanding the existing national committee to include specialists with demonstrated expertise in Byzantine monuments.
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Consideration by the World Heritage Committee of placing the Historic Areas of Istanbul on the List of World Heritage in Danger.
The proposed international committee would help assess interventions against both structural safety needs and the protection of Hagia Sophia’s Outstanding Universal Value—the cultural significance underlying its World Heritage status. The communication also supports participation by the communities and religious traditions for which the monument holds significance.
Beyond the current works, the Chair raises questions about whether management arrangements following the conversion of Hagia Sophia and Chora into mosques adequately safeguard their multilayered heritage and public access. It requests consideration of these concerns within UNESCO’s broader cultural and intercultural mandate.
The communication is signed by Professor Dr Stavros Katsios, Chairholder and Director of the Laboratory for Geocultural Analyses at the Ionian University.
The Chair acts in its academic and research capacity and does not represent any State Party. Its intervention seeks constructive dialogue, independent verification and scientific cooperation to support the long-term protection of Hagia Sophia and the Historic Areas of Istanbul.
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