"about:wikidata"=>"Q1692044","about:wikipedia"=>"nl:Johan Luzac","material"=>"metal","memorial"=>"plaque","start_date"=>"1909"
"inscription"=>"Ligplaats van het kruitschip gesprongen 12 januari 1807","material"=>"stone","memorial"=>"hazard_memorial"
"about:wikidata"=>"Q84227","about:wikipedia"=>"nl:Paul Ehrenfest","material"=>"stone","memorial"=>"plaque"
"location"=>"wall","subject"=>"Lucretia Wilhelmina van Merken","subject:wikidata"=>"Q3265974"
"memorial"=>"plaque","start_date"=>"08-06-2023","subject:wikidata"=>"Q370069","subject:wikipedia"=>"nl:Józef Wybicki"
"material"=>"metal","memorial"=>"plaque","subject:wikidata"=>"Q315163","subject:wikipedia"=>"nl:Josephus Justus Scaliger","wikimedia_commons"=>"Category:Joseph Justus Scaliger"
"memorial"=>"war_memorial","url"=>"https://www.tracesofwar.nl/sights/109287/Indi%C3%ABmonument-Leiden.htm","wikidata"=>"Q14917889","wikimedia_commons"=>"Category:Indië-monument, Leiden"
"memorial"=>"war_memorial","url"=>"https://www.tracesofwar.nl/sights/56999/Herdenkingsmonument-bij-Molen-De-Valk-Leiden.htm","wikidata"=>"Q27891853","wikimedia_commons"=>"Category:Bevrijdingsmonument, Leiden"
"artist_name"=>"Guido Geelen","inscription"=>"DANK MONUMENT. TER HERINNERING AAN DE MENSEN DIE HUN LICHAAM AFSTONDEN AAN DE WETENSCHAP","material"=>"bronze","memorial"=>"sculpture","start_date"=>"2018-10-16"
"memorial"=>"stolperstein","wikimedia_commons"=>"File:LeidenStolpersteineRijnsburgerweg116-BenjaminMeijer.jpg"
"memorial"=>"sculpture","subject:wikidata"=>"Q116034","subject:wikipedia"=>"nl:Daniël Wyttenbach"