"The earliest archeological remains of a synagogue building on the island of Delos in the Aegean indicate a late second-century or possibly mid-first century BC date of construction, while earlier inscriptions and papyri have been discovered in Egypt, commencing with the third century BC."- Levine, Lee. The Ancient Synagogue: The First Thousand Years. New Haven, Conn.: Yale University Press. ISBN 0-300-10628-9.
"A number of very early synagogues date from the 1st-century AD. A synagogue dating from between 75 and 50 BC has been uncovered at a Hasmonean-era winter palace near Jericho."-http://www.archaeology.org/9807/newsbriefs/israel.html,
Israel's Oldest Synagogue. http://www.jewishsf.com/content/2-0-/modul...y/story_id/8390/edition_id/159/format/html/displaystory.html
"More than a dozen Second Temple era synagogues have been identified by archaeologists."-http://www.pohick.org/sts/index.html 2010-09-08. Retrieved 2012-08-29.
"The oldest Samaritan synagogue, the Delos Synagogue dates from between 150 and 128 BC, or earlier and is located on the island of Delos."-http://www.pohick.org/sts/delos.html Retrieved 2012-08-29.
"The Jericho Synagogue, the oldest, securely dated, mainstream Jewish synagogue in the world was built between 70 and 50 BC at a royal winter palace near Jericho."-http://www.pohick.org/sts/jericho.html 1998-03-29. Retrieved 2012-08-29.
"The oldest synagogue fragments are stone synagogue dedication inscriptions stones found in middle and lower Egypt and dating from the 3rd century BC"-http://www.pohick.org/sts/egypt.html
This one was discovered in 2009, also once a city skeptics insisted didn't exist till the 2nd century, like Nazareth.
The Wadi Qelt Synagogue located in Wadi Qelt a mile southwest of Jericho, is the oldest synagogue found to date. It dates from between 70 and 50 BC, and was built as part of the Hasmonean royal winter palaces complex in the desert oasis of Jericho.
Where Simon was from
the pre-70 dating of the inscription has been firmly established through both paleography and an analysis of the find's archaeological context. Not only do the inscription's letter-forms closely match those of other inscriptions dated to the Second Temple period, but all of the pottery and artifacts discovered with the dedication also date to this era.
Most recent excavations have revealed two synagogues, a white limestone synagogue dating from the fourth to fifth centuries CE, and a black basalt synagogue dating from the first half of the first century CE. Only foundation walls, gray marble column fragments and a cobblestone floor remain from the earlier structure, which measured 24.5 by 18.7 meters on the exterior and possessed walls over a meter thick.
View of the IV-V century Limestone synagogue, looking north. This structure was built on top of an earlier synagogue that was founded in the first century CE and constructed out of basalt. Only the foundation walls and cobblestone floor remain from this earlier building (see below). (Column drums made out of gray marble have also been discovered in a lower stratum of fill material.) It is thus the basalt synagogue which is referred to in the four Gospels.
Upon taking office in Caesarea, Florus began a practice of favoring the local Greek population of the city over the Jewish population. The local Greek population noticed Florus' policies and took advantage of the circumstances to denigrate the local Jewish population. One notable instance of provocation occurred while the Jews were worshiping at their local synagogue and a Hellenist sacrificed several birds on top of an earthenware container at the entrance of the synagogue, an act that rendered the building ritually unclean. In response to this action, the Jews sent a group of men to petition Florus for redress. Despite accepting a payment of eight talents to hear the case, Florus refused to listen to the complaints and instead had the petitioners imprisoned.
Josephus, The Wars of the Jews, Book 2, Chapter 14, Section 5
Not Synagogue related, but evidence for Nazareth.