NFDI4Culture provides the Culture Knowledge Graph to facilitate FAIRness in its communities. It provides a lightweight infrastructure that interconnects research data from diverse domains such as architectural studies, art history, musicology, performing arts, and media studies. To allow further exploration of resources across individual knowledge silos, the graph is designed to be compatible with other research areas as well. It requires data providers to implement the Culture Graph Interchange Format, a subset of schema.org classes and properties, either as embedded metadata, an API, or a SPARQL endpoint that can be harvested, or as an RDF data dump. Connections between resources are established via controlled vocabularies, and ingested data is made available via the Culture Information Portal's SPARQL endpoint. After introducing the infrastructural need, the paper reviews comparable solutions, describes the graph, discusses technical choices, and outlines our engagement within and beyond NFDI4Culture.