<p>Ahlat Stone, a distinctive ignimbrite widely used in the historical architecture of Eastern Türkiye, represents an exceptional interplay between geology, culture, and craftsmanship. In this study, Ahlat Stone is assessed as a potential candidate for Heritage Stone recognition under the framework of the International Union of Geological Sciences Heritage Stone Subcommission (IUGS-HSS), by integrating evidence from its geological setting, petrographic–geochemical characteristics, engineering properties, durability and long-term cultural use with quarrying continuity. Laboratory testing, field observations and historical documentation are integrated to assess the stone geological, physical–mechanical and cultural attributes. Petrographic analyses indicate a pumice and lithic-rich welded ignimbrite characterized by high porosity and moderate compressive strength. Durability tests further suggest that the stone performs satisfactorily under freeze–thaw and salt crystallization cycles, supporting its long-term use in Seljuk and Ottoman monuments, including tombstones, mosques and bridges across the Lake Van Basin. Ahlat Stone occurs in several widely recognised colour varieties (beige, red, brown and black) and its ease of carving and proven longevity in architectural heritage underline its geo-cultural significance. Overall, the evidence indicates that Ahlat Stone aligns with the fundamental requirements for consideration as a Heritage Stone, supporting its nomination as a representative material of Türkiye’s geoheritage.</p>