What remains of the main synagogue of Barcelona, which originated in the 6th century, is two cellar-like rooms, which have been restored by Asociación Call de Barcelona. Reclaimed in 1996, the synagogue is considered the oldest in Spain and one of five surviving medieval synagogues in Europe. The association also gives guided tours of the Jewish quarter, which was destroyed on Aug. 5, 1391 when Jews were killed, forced to flee or had to convert to Christianity. Not the easily place to find, it is at Carrer de Marlet 5, near the Plaça Sant Jaume. Hours: Tues. - Sun., 11 a.m. - 2:30 p.m. and 4 p.m to 7:30 p.m.