Survey and Analysis of Hieroglyphic Inscriptions in the Postern of Yerkapı–Ḫattuša

Yerkapı, a prominent structure within Ḫattuša, the capital of the Hittite Empire (17th–12th century BC), exemplifies the sophisticated architectural and cultural practices of this ancient civilisation. The monument, encompassing a Sphinx Gate and an underground tunnel (postern) featuring 249 hieroglyphic inscriptions, is hypothesised to have served ceremonial rather than defensive purposes. This study employs a multidisciplinary approach to document, analyse, and interpret the inscriptions and their architectural context through advanced methodologies. High-resolution 3D digitisation was conducted using drones, terrestrial laser scanning, and photogrammetric techniques, enabling the creation of detailed models of the site. Specific focus was given to the postern, with comprehensive surveys delineating the geometries of the inscriptions and their spatial relationships to the Sphinx Gate. Diagnostic pigment analysis provided insights into the mineralogical and chemical composition of the red figures, further informing the interpretation of the hieroglyphs. The integration of 3D models and petrographic data allowed for the identification of previously unobservable details and facilitated a sequential reading of the inscriptions within their architectural framework. The findings emphasise Yerkapı’s function as a site of symbolic and ritual importance, thereby advancing our comprehension of Hittite ceremonial practices and establishing a methodological paradigm for the integration of digital archaeology with the study of geo-materials in the investigation of complex ancient monuments.