Recommendation for Geo ontology and internet data source

To sell the idea that StarDog can integrate external knowledge and data,
I want to focus on importing a Geospatial ontology with a public data source.

The Geospatial ontology could be simple city in-a state in-a country, i.e. am not interested in calculating distance between points or regions in a map.

The key feature is that the data source must be available on internet and that StarDog has a connector that can reach the data source.

My data has has a location that is in-a city name or lat-long
I would like to hook my data set into the geospatial data set.
Any recommendations?

Geonames