Rav Yirmeya bar Abba teaches in the name of Rav that there are two rules with regard to eiruvin that are limited by their places.
Burganin do not operate in Babylonia
Pasei bira’ot (upright boards surrounding a well) do not operate outside of Israel.
Burganin are huts used by watchmen on the roads. Some of them were well-constructed and were used as defensive positions for the military. The guards lived in these structures, guarded the fields and delivered reports and messages to the government. Other burganin were poorly made and were no more than shacks on the side of the road. The source for the word burganin may be Greek in origin, but it is likely from the German “Burg” meaning “fortress” or “small settlement.” The term was carried on the lips of Roman soldiers who were stationed on the border with Germany throughout the Roman Empire – even to the language of the Talmudic Sages.
The significance of these structures for Jewish law is that on Shabbat a person is limited in his ability to travel more than 2,000 amot outside of his city. When deciding where the edge of the city lies, however, if they are close enough (about 70 amot) to the city, buildings like these can be considered part of the city allowing one to walk significantly further away from the city limits on.
The Gemara explains: The law with regard to huts does not apply in Babylonia because floods are common there; and since the huts are liable to be swept away by the floodwaters, they are not regarded as dwellings. The allowance with regard to upright boards surrounding a well does not apply outside of Eretz Yisrael, because yeshivot are not common there, and the allowance was only granted to those traveling for the sake of a mitzva such as Torah study. But we do say the opposite, i.e., we apply the law of huts outside of and we apply the allowance of upright boards surrounding a well in Babylonia.
The pasei bira’ot are the deyomadin of the Mishna at the beginning of the perek. According to the Gemara, they apply in Babylonia but not in other countries, because other countries do not have Metivta – Torah study halls.
It is clear from this ruling, as well as from other similar statements in the Gemara, that the Sages saw Babylonia as having a higher status than other countries in the Diaspora. This stemmed from the large Jewish population, including cities and towns that were almost entirely populated by Jews and a network of Yeshivot and study halls. As an example, according to this opinion, the leniency of pasei bira’ot offered to olei regalim (Festival pilgrims) in Israel were applied to students traveling to Yeshivot in Babylonia, as well.
There is a second version of Rav Yirmeya bar Abba’s teaching brought in the Gemara, which states that neither burganin nor pasei bira’ot work outside of Israel – not in Babylonia nor beyond.