I am currently working on a project involving a spatial ontology. However, it is not very clear to me to what extent spatial ontologies are available in practice (and not only sketched in scholar papers). LinkedGeoData seems to be a good choice, as I am gathering spatial data (e.g. amenities, etc) from OSM, still it seems that I can't download the RDF triples directly from their SPARQL endpoints (see some OSM Example Queries), and also I'm not sure whether I can enrich (and extend) such ontology with new open-data from third-party sources (in addition to OSM nodes and ways).
Once I select a node, I need to gather as many information as possible about it (e.g., considering a shop: position, leisure/work, similar places, ...), possibly integrating the ontology with third-party open data. As such, I need somehow to be able to extend LinkedGeoData knowledge with external sources. How can I add this new data if not by downloading the ontology, its instances, and enrich the ontology with my data?
Am I missing the scope of LinkedGeoData? Are there any (real) alternatives to it?