According to the local Greek scholar Panayiotis Aravantinos, a synagogue destroyed in the 18th century bore an inscription, which dated its foundation in the late 9th century AD. The existing synagogue is located in the old fortified part of the city known as ""Kastro"", at 16 Ioustinianou street. Its name means "the Old Synagogue". It was constructed in 1829. Its architecture is typical of the Ottoman era, a large building made of stone. The interior of the synagogue is laid out in the Romaniote way: the Bimah (where the Torah scrolls are read out during service) is on a raised dais on the western wall, the Aron haKodesh (where the Torah scrolls are kept) is on the eastern wall and at the middle there is a wide interior aisle. The names of the Ioanniote Jews who were killed in the Holocaust are engraved in stone on the walls of the synagogue.