Archaeologists in Japan are baffled by the peculiar discovery of ten ancient Roman coins within the ruins of a castle in the Okinawa prefecture of southern Japan. The coins themselves date from between 300 and 400 A.D., while the castle in which they were found was operational between the 12th and 15th centuries, and simply put, no one is entirely sure how the ancient Roman currency made its way there. Indeed, the presence of the coins is so strange that the archaeologist first charged with examining them believed the whole thing could be a hoax.
The coins were uncovered during excavations beneath the remains of Katsuren Castle,a UNESCO World Heritage Site, which sits on the Katsuren Peninsula surrounded by the Pacific Ocean. And it's been a pretty rich site for archaeologists, with discoveries of precious tile and Chinese ceramics indicating that the Castle was point of trade with with other parts of Asia up until the Castle ceased to be used in 1611.
Which is all well and good, until one finds a handful of ancient Roman coins--the likes of which have never been found in any other part of Japan. The first of the coins were found by Toshio Tsukamoto, a researcher from Gangoji temple cultural properties department, who explained to CNN:
I'd come to analyze artifacts like Japanese samurai armor that had been found there when I spotted the coins... I'd been on excavation sites in Egypt and Italy and had seen a lot of Roman coins before, so I recognized them immediately.
The faces of the coins were fairly worn, but x-ray examination showed that the 1.6-2cm diameter coins feature an image of Constantine I, as well as of a soldier holding a spear. 17th century Ottoman coins were also discovered nearby.
While archaeologist Hiroyuki Miyagi first thought the coins might have been dropped at the site by tourists, as a hoax, the more probable theory is that they found their way to Katsuren along long, winding trade routes. Though the castle itself may not have been trading with the west, they were enjoying lively business with China, Korea and southeast Asia.
So it may be possible that the coins of the Roman Empire were carried along trade routes to other parts of Asia, before being exchanged on the Katsuren Peninsula, and archaeologists plan to further examine other artifacts at the site, in tandem with the coins, in an effort to determine the coins' exact path.
Katsuren Castle photo via kanegen