What cities are around the sea which flows into Marmara?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/inflow> <http://dbpedia.org/resource/Sea_of_Marmara> . ?x <http://dbpedia.org/property/cities> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Sea>}
Sea_of_Marmara