Garum, the strong tasting fish sauce so beloved of the Romans, was traditionally made in Italy. Consisting of fermented fish in brine, sometimes with added wine, herbs and spices, it was a staple of the Roman diet. Pompeii was one of the towns where the ‘best’ versions of it was made (see Mary Beard’s excellent book Pompeii), but it was also made in Spain. Around 50 AD, a ship carrying over 1200 amphorae of it sank off the Spanish coast. It wasn’t found again until 2000. See an interesting National Geographic article on it here.