The Kahal Kadosh Yashan synagogue known as the “old synagogue” can be found within the castle’s walls along Justinian Street. Its foundation is believed to date back to the Byzantine period. Today’s surviving structure was renovated in 1987 and survives thanks to the efforts of former Ioannina mayor Dimitrios Vlahides. He convinced the Nazis not to destroy it, claiming that the Greeks wished to convert it into a library. He also managed to save dozens of Jewish artefacts found within the church that were later given to returning survivors of the holocaust.