RDFMapper: an RDF-Based Web Mapping Service :

RDFMapper is a web service that searches an RDF or RSS file for resources with geographic locations, and returns a map overlayed with dots representing located resources. Clicking on a dot displays a web page representing the clicked resource. (...) The base URL of the service is http://www.mapbureau.com/rdfmapper/v1.php

RDFmap defines a set of RDF classes and properties for representing basic geographical information.