Josefov is just behind the Old Town Square of Prague, Staroměstské náměstí. Josefov was, ironically, preserved by the Nazis, as a Museum to commemorate the "extinct" Jewish population which had thrived there for centuries.
Known as the Jewish Ghetto, many residents ended up in Czech concentration camps during the occupation of the Third Reich. Older synagogues display layers of tombstones in the yards. Remnants of the old barrows are still visible although much of the original ghetto has now been replaced by upscale stores.
Below is the unique and historic "Old-New Synagogue" (Staronová synagoga). While it was new at the time it is now the oldest functioning synagogue in Europe.