500 Yuan Return of Macau to China

Issued to mark the handover of Macau from Portugal on December 20, 1999 — the last European colonial transfer in Asia — this five-ounce piece was produced in a mintage of just 1,000 examples. Portugal had administered Macau since the 1550s, making it one of the longest-running colonial arrangements in history, over 400 years by the time the territory reverted to Chinese sovereignty under the "one country, two systems" framework negotiated in the 1987 Sino-Portuguese Joint Declaration.