In the old days, quarantines were a common way to prevent spreading diseases. Many old cities throughout Europe had such a system in place due to different disease outbreaks.
E.g. the old city of Dubrovnik, once an independent Republic, had a set of interconnected buildings located 300 m away from its city walls called Lazzarettos of Dubrovnik. Everyone coming from affected areas would have to spend a month there before entering the city.
https://www.bbc.co.uk/news/uk-51292590 
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In the old days, quarantines were a common way to prevent spreading diseases. Many old cities throughout Europe had such a system in place due to different disease outbreaks.
E.g. the old city of Dubrovnik, once an independent Republic, had a set of interconnected buildings located 300 m away from its city walls called Lazzarettos of Dubrovnik. Everyone coming from affected areas would have to spend a month there before entering the city.
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