It is not well known that there were two Jewish temples in ancient Egypt. They do not form part of our traditional history, which concentrates on the going down into Egypt and the coming out of it, as based on the Torah accounts, for which there is little or no contemporary corroboration. But the two temples, though well attested by contemporary sources, have received little attention from our tradition.
One of these temples has been known about for nearly 2,000 years from Josephus Flavius and the Talmud, and its site was claimed to have been found just 100 years ago, but it has now been lost again. The other was never known of till just a hundred years ago and its site has only recently been discovered. The first is the Temple of Onias at Leontopolis dating to about 200 BCE, and the second is the Temple of Elephantine dating to 300 years earlier, to about 500 BCE.
THere's also a small Jewish community in Cairo, oddly enough, and a temple/synagogue. IIRC, it's near the old Coptic area.