Evidence of contacts with the civilizations of Classical Antiquity—primarily with the Roman Empire, but sometimes also with other cultures of the age—have been based on isolated archaeological finds in American sites that originated in the Old World. The Bay of Jars in Brazil has been yielding ancient clay storage jars that resemble Roman amphorae for over 150 years. It has been proposed that the origin of these jars is a Roman wreck, although it has been suggested that they could be 15th or 16th century Spanish olive oil jars.