Türkmen Valley is a large-scale masterplan project strategically located between Mardin Airport, the historic city center, and the city’s developing urban axis. Covering approximately 503 hectares, the project aims to transform a formerly industrial and degraded valley into a sustainable, low-density, and landscape-oriented urban district that adds long-term value to the city. The masterplan is shaped by extensive urban, cultural, environmental, and socio-economic analyses, responding to Mardin’s unique historical identity, topography, climate, and multicultural structure. Residential areas are positioned on suitable upper terrains, while the valley floor accommodates cultural, recreational, tourism, health, and social facilities. A strong green and recreational spine, supported by water elements, connects public parks, urban forests, and themed landscape areas. The design integrates cultural facilities, museums, congress and exhibition centers, tourism and health-oriented developments, educational and social infrastructures, and local commercial units inspired by traditional bazaars. Architectural language reinterprets Mardin’s vernacular elements—such as courtyards, arcades, abbaras, and local limestone—through a contemporary and sustainable approach. The result is a horizontally oriented, low-rise, and environmentally conscious urban vision that respects local heritage while addressing future needs.