...how about those Roman coins?
The ones found in the foundations of a Japanese castle.
Yes, in Japan.
Archaeologists are not sure how the coins, dated back to at least 400AD, got to be buried under the ruins of Katsuren Castle on Okinawa Island - but they aren't a hoax. That's been thoroughly, well, debunked.
Presumably along the Silk Road - finding them in China makes sense, given the Romans liked Chinese silk. But how they got to Japan is less clear - the castle traded with the Chinese but has no other connections to Europe. Heck, maybe somebody was collecting foreign coins...