During the first season of excavations at Masada in 1963, Yigael Yadin and his crew discovered a strange structure adjoining the northwestern wall. The building was not like any other they had thus far excavated in the casemate wall. It contained clay-plastered benches along all the walls and two rows of pillars in the center of the main room. The inside dimensions were twenty-seven by thirty-six Roman feet (one Roman foot equals 0.2957 meters). A second, smaller room was on the western side and immediately adjacent to the casemate wall. On the floor were coins of the period of the revolt.
Because the entrance faced east and the building as a whole was oriented toward Jerusalem and because one ostracon found on the floor was inscribed "priestly tithe" and another "Hezekiah," Yadin decided that this structure must have been a synagogue. Although the original structure apparently had been modified somewhat by the Zealots, it was quite likely built as a synagogue and used as such even by Herod or his entourage. This find was especially significant, because until that time, no synagogue earlier than the end of the second century A.D. had been discovered in Israel—certainly none from the Second Temple period. This, in spite of the fact that the New Testament and Josephus's works contain numerous literary attestations of the presence of synagogues during that period.