query: embed.html##defaultView:Map
  SELECT ?item ?itemLabel ?typeLabel ?location ?image ?layer WHERE {
    ?item wdt:P31/wdt:P279* wd:Q49844 .
    ?item wdt:P31 ?type .
            OPTIONAL {?item wdt:P625 ?location}
            OPTIONAL {?item wdt:P18 ?image}
    VALUES ?type { wd:Q7407968 wd:Q49844 wd:Q58663 }
    BIND(
         IF(?type = wd:Q7407968, "wall box", 
         IF(?type = wd:Q49844, "post box",
         IF(?type = wd:Q58663, "pillar box",
              ""))) AS ?layer).  
    
    SERVICE wikibase:label {
  		bd:serviceParam wikibase:language "en" . }
    }