Officials in Japan's southwestern prefecture of Okinawa say copper coins found in the ruins of a local castle are thought to date back to the Roman and Ottoman empires. They say the find demonstrates the wide extent of trade engaged in by Okinawa in the past.
The board of education in Uruma City conducted an excavation of the ruins of Katsuren-Jo, a World Heritage site, in 2013. It found 4 copper coins believed to be from the Roman Empire in the 3rd to 4th centuries, and another thought to be from the Ottoman Empire in the late 17th century.
The castle is said to have prospered during the Ryukyu Kingdom in the 14th and 15th centuries by trading with China and Thailand. Ryukyu is an old name for Okinawa.
Education board officials and experts say it may be the first time that Roman or Ottoman coins have been discovered in ruins in Japan.
Okinawa International University lecturer Hiroki Miyagi calls the discovery remarkable. He says the people of Ryukyu are known to have traded with China during the Edo period. He added that the coins indicate the possibility that Ryukyu also had exchanges with western countries.