A few days ago, I read this article about Roman coins that were discovered in Japan. And not like “were lost from a modern collection” discovered, actually discovered as having been in Japan contemporary with the Roman Empire.
“Okinawa’s trade with China and Southeast Asia was thriving at the time and the finding is ‘precious historical material suggesting a link between Okinawa and the Western world,’ the board of education said,” according to The Japan Times (via NPR).

First off, this isn’t completely earth shattering (although it is definitely incredibly intriguing). The Romans and the Chinese were aware of each other, even to the point of Roman emissaries traveling to China to each other during the reign of Marcus Aurelius. Even before these emissaries made direct contact, trade between these two empires was already established by way of middle men. There’s even a (unproven) legend of a Roman battalion engaging in battle with (or alongside) Chinese forces, and a remote village in China where the villagers claim to be descended from Roman settlers.
Of course, the presence of Roman coins in Japan doesn’t mean that Marcus Aurelius’s emissaries made it that far. “We don’t think that there is a direct link between the Roman empire and Katsuren castle, but the discovery confirms how this region had trade relations with the rest of Asia,” Masaki Yokou, a spokesperson from Uruma city’s Board of Education, told CNN.
That seems to be the more likely story: that the coin eventually found its way from China to Japan on its own, perhaps as a curiosity, rather than that an actual Roman managed to make the trek. Perhaps further research will shed more light on this. And perhaps not. Either way, the fact that such far-flung civilizations were aware of each other is a fact that often goes overlooked.