Some Facts: An eruv cannot be made in a reshus harabim. Many eruvin are made in cities nowadays. Cities are much bigger now than they were thousands of years ago. Yet it seems that in those ...
When did Jerusalem first get an eruv for carrying on Shabbos? I've heard that Rav Moshe Feinstein pointed out that it didn't have one in Talmudic times. So when did they get one?
Were there any Shtetlach in pre war Europe that had an Eruv? Which ones?