"archaeological_site"=>"field_system","historic:civilization"=>"celtic","name:en"=>"celtic fields"
"archaeological_site"=>"megalith","heritage"=>"2","megalith_type"=>"dolmen","ref"=>"D5","wikidata"=>"Q2441019"
"archaeological_site"=>"megalith","heritage"=>"2","megalith_type"=>"dolmen","ref"=>"D2","wikidata"=>"Q2090122"