About: http://webisa.webdatacommons.org/236659085

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Walls would help a city control immigration and trade, keeping out undesirables would be vital to a city remaining healthy especially preventing epidemics that could devastate a city.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com