What is {coordinate location} of {Daugava River} that is {applies to part} is {river mouth} ?
At what place is located the mouth of the Daugava River?
Where is the mouth of the Daugava River located?
SELECT ?u WHERE { resource:Daugava_River property:coordinate_location ?s . ?s property:applies_to_part resource:river_mouth . ?s property:coordinate_location ?u }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q8197> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P625> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P518> <http://wikidata.dbpedia.org/resource/Q1233637>
} 

SELECT ?obj WHERE { wd:Q8197 p:P625 ?s . ?s ps:P625 ?obj . ?s pq:P518 wd:Q1233637 }