query: SELECT ?beachLabel (group_concat(?beach) AS ?items) (count(?beach) AS ?cnt) WHERE {
    ?beach (wdt:P31/wdt:P279*) wd:Q40080.
    SERVICE wikibase:label { bd:serviceParam wikibase:language "es,en,ca,gl,eu". }
    ?beach wdt:P17 wd:Q29.
  }
  GROUP BY ?beachLabel
  HAVING ( ?cnt>1 )