A Semantic Backbone for Heritage Digital Twins: Ontology Development and Knowledge Graph Generation

This study develops an ontology-driven framework for the semantic enrichment of the Ephesus Ancient City within a Heritage Digital Twins (HDT) context. The proposed approach integrates heterogeneous cultural heritage data into a unified semantic structure, enabling consistent representation of complex relationships. A domain-specific ontology is developed, followed by the construction of a knowledge graph in Neo4j to support structured querying. The framework moves beyond visualization-oriented digital twins by introducing a knowledge-centered semantic layer intended to support future reasoning and decision-making capabilities. Rather than constituting a complete digital twins system, the proposed approach establishes a semantic backbone that can serve as a foundation for future Heritage Digital Twins implementations. The Ephesus case suggests the practical applicability of the framework on a complex CH site. The results suggest a scalable and semantic foundation for developing interoperable Heritage Digital Twins.