Scientists based at The Field Museum have unearthed a rare, 600-year-old coin off the coast of Kenya.

The coin, issued by Emperor Yongle of China, has been described as proof that Africa and China were trading before Europeans had mapped Africa's coast.

The silver and copper coin is called "Yongle Tongbao" - and the hole in the center was to keep it on a belt. The coin was issued by the Ming Dynasty's Emperor Yongle, who ruled from 1403-1425AD, and was instrumental in constructing Beijing's Forbidden City.

The coin is currently off display at the Field in Chicago, where Chapurukha M. Kusimba, curator of African Anthropology at The Field Museum, is reportedly studying to make sure it is not a counterfeit.