Dating from the reign of the emperor Claudius (41-54 CE), the Ostia Synagogue located in ancient Ostia Antica, the seaport of Imperial Rome, is the oldest synagogue in Europe and one of the oldest synagogues in the world.
"There is a scholarly debate about the status of the synagogue building in the 1st century CE, with some maintaining that the building began as a house only later converted to use as a synagogue, and others arguing that it was in use as a synagogue from the 1st century.
"In its earliest form, the synagogue featured a main hall with benches along three walls; a propyleum or monumental gateway featuring four marble columns; and a triclineum or dining room with couches along three walls. There was a water well and basin near the entryway for ritual washings. The main door of the synagogue faces the southeast, towards Jerusalem.
"An aedicula, to serve as a Torah Ark added in the 4th century CE. A donor inscription implies that it replaced an earlier wooden platform donated in the 2nd century CE, which itself had been replaced by a newer Ark donated by one Mindus Faustus in the 3rd century CE" (Wikipedia article Ostia Synagogue, accessed 01-04-2014).