This paper abstract presents an approach and first results of creating a global LOD service and semantic portal, SampoSampo, based on a network of interlinked Cultural Heritage knowledge graphs (KG) of different application domains. In this way, a more comprehensive global view for searching, exploring, and analyzing the interlinked KGs can be provided than by using local KGs separately. The SampoSampo LOD service can be used as a web service for providing IRI identifiers for aligning new datasets with the national DARIAH-FI research infrastructure on which SampoSampo is based, and for assessing the quality of data in different KGs by comparing their metadata. The portal underway can be used for searching and exploring the local KGs by with a single user interface (UI) and for implementing novel application perspectives based on relational search, where semantic “interesting” associations (relations) between entities, such as persons, organizations, and places in the global KG, can be searched for and natural explanations for them be created.