Geoseer
Geoseer was developed in order to provide an easy search engine that can locate spatial data. It was developed by JISC. As they state in their About page:
”There are hundreds of thousands of public-facing geospatial web-services out there using the Open GeoSpatial (OGC) standards (Web Map Server (WMS), Web Feature Service (WFS), Web Coverage Service (WCS), and Web Map Tile Service (WMTS)) to serve data, but they have only limited discoverability. We wanted to create a search engine that would bring all of these services into a single place, so we created GeoSeer.
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All of these results are datasets made available via standards compliant geospatial web services. To access them, you'll need to use a GIS (Geographic Information System). QGIS is a popular and free GIS and supports all of these standards and many other spatial and non-spatial formats besides. There are lots of tutorials online explaining how to add services - this search is a good start.”