In recent years several solutions and standards have emerged to access and transfer 3D geospatial content over the internet. These solutions were developed for various technical and commercial reasons. They use different distribution mechanisms and are optimized for user requirements and bandwidth situations. As each of these co-existing solutions binds the user to an approach, it is challenging to access a variety of 3D content from different providers. 3D GeoVolumes address this challenge by providing a resource model and corresponding API to integrate various approaches into a single, open standards-based solution. OGC API - 3D GeoVolumes allows efficient discovery and access of 3D content in multiple formats based on a space-centric perspective.