BEIT SHEMESH, Israel — The carved stone block is about the size of an occasional table. It has held its secrets for two millenniums. Whoever engraved its enigmatic symbols was apparently depicting the ancient Jewish temples.

But what makes the stone such a rare find in biblical archaeology, according to scholars, is that when it was carved, the Second Temple still stood in Jerusalem for the carver to see. The stone is a kind of ancient snapshot.

And it is upending some long-held scholarly assumptions about ancient synagogues and their relationship with the Temple, a center of Jewish pilgrimage and considered the holiest place of worship for Jews, during a crucial period, when Judaism was on the cusp of the Christian era.

Known as the Magdala Stone, the block was unearthed in 2009 near the Sea of Galilee in northern Israel, where a resort and center for Christian pilgrims was going to be built. Government archaeologists are routinely called in to check for anything old and important that might be destroyed by a project, and in this case they discovered the well-preserved ruins of a first-century synagogue and began excavating.