Geospatial Linked Data is an emerging domain, with growing interest in research and industry. The growing sources of open-source geospatial Linked Data need to be interlinked and easily integrated with private and industrial linked data clouds, e.g., in the agricultural domain. The presented paper analyzes common link discovery tools for the feasibility of big linked data processing. Further, it introduces Geo-L, a system for discovery of RDF spatial links based on topological relations. Experiments show that the proposed system improves state-of-the-art spatial linking processes in terms of mapping-time and -accuracy, as well as concerning resources retrieval efficiency and robustness.