Ten historic city-wall examples: Dubrovnik, Avila, Carcassonne, York, Lucca, Xi'an, Mdina, Marrakesh, Cartagena de Indias and Nuremberg. This is an architectural selection, not a ranking by age, length or preservation. Carcassonne underwent major nineteenth-century restoration, and Lucca's walls became a city park. Mdina is on the UNESCO tentative list, not the inscribed World Heritage List. Current visitor access is not asserted. Photo authors, source pages and open licenses follow below. Walls of Dubrovnik: Zysko serhii; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:The_sea_and_walls_of_the_old_city._2018.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Avila: Discasto; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Murallas_de_%C3%81vila_%288_de_agosto_de_2015%2C_%C3%81vila%29.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Carcassonne: Peulle; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Cite_de_Carcassonne_29.JPG; resized and fitted to portrait frame; derived image retains the source license. York City Walls: Russel Wills; CC BY-SA 2.0; https://creativecommons.org/licenses/by-sa/2.0/; https://commons.wikimedia.org/wiki/File:City_walls_at_York_-_geograph.org.uk_-_5310428.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Lucca: Federica gagliardi; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Lucca_vista_dalle_Mura_-_lato_esterno.jpg; resized and fitted to portrait frame; derived image retains the source license. Xi'an City Wall: Gary Todd from Xinzheng, China; CC0 1.0; https://creativecommons.org/publicdomain/zero/1.0/; https://commons.wikimedia.org/wiki/File:Xi%27an_City_Wall_South_Gate_%289912031106%29.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Mdina: Hans A. Rosbach; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0/; https://commons.wikimedia.org/wiki/File:Mdina_-_Wall_20100226-1.JPG; resized and fitted to portrait frame; derived image retains the source license. Walls of Marrakesh: Land Rover MENA; CC BY 2.0; https://creativecommons.org/licenses/by/2.0/; https://commons.wikimedia.org/wiki/File:City_walls_of_Marrakech_at_sunset.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Cartagena de Indias: Laslovarga; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Cartagena%2C_Colombia_-_Laslovarga_%2810%29.jpg; resized and fitted to portrait frame; derived image retains the source license. Walls of Nuremberg: Tilman2007; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0/; https://commons.wikimedia.org/wiki/File:N%C3%BCrnberg%2C_Stadtmauer%2C_Frauentormauer%2C_Kasemattenturm_IX%2C_Mauerturm_Rotes_E%2C_001.jpg; resized and fitted to portrait frame; derived image retains the source license.