A 9-kilometer network of tunnels has been discovered beneath Hagia Sophia in Istanbul

Large-scale restoration work being carried out at the Hagia Sophia in Istanbul has led to a sensational discovery: a complex system of underground passages and tunnels, with a total length of 9 kilometers, lies hidden beneath the building. This was reported by the Orthodoxia News Agency ( ).

According to Turkey’s Minister of Culture and Tourism, Mehmet Nuri Ersoy, the current restoration project encompasses not only the visible part of the famous architectural monument but also its hidden underground levels. Specialists have already begun the complex work of clearing the tunnels of silt and mud, and are also conducting comprehensive monitoring of humidity levels and the structural stability of the buildings to prevent further damage.

According to the minister, collapses have been recorded in several sections of the network, hindering free movement. Nevertheless, work on restoring the underground structure is progressing successfully. Authorities are considering the possibility of partially opening these areas to the public in the future: if experts confirm the safety of these sections, visitors will have a unique chance to see the “invisible side” of the great cathedral, which has remained inaccessible for centuries.