Dr. Lee Levine came forward in writing and in SBL sessions and elsewhere and made emphatically clear that there were indeed purpose built synagogues even in Jesus' day and thereafter, and that in fact the practice may well pre-date the Herodian era. One of the sites Levine most based his argument on was in the lower Golan Heights, at the village of Gamla, sometimes also called Gamala (from the Hebrew word for camel, because the hill on which the village rests looks like the hump, or perhaps the nose of a camel from a certain angle). As it turns out, Levine was absolutely and positively right. A little of the history of Gamla is in order, since it is not a city mentioned in the Bible.
The village seems to have begun as a Selucid outpost in the 2nd century B.C. where a fort was established as a sort of early warning signal for those living in the Holy Land. It seems to have begun to become a civilian settlement of Jews sometime later in that century. Bible readers may know this site if they have read Josephus' Antiquities, in particular 13.394 which recounts how Josephus himself, as a Jewish commander early in the Jewish war in the A.D. 60s fortified this outpost as one of his main lines of defense of Galilee from Roman attack.