A one-foot-wide bronze mask dating to around 1100 b.c. emerges from beneath a bronze vessel containing cowrie shells during recent excavations at the site of Sanxingdui in China’s Sichuan Province.

Two swords once carried by samurai have been found during excavations in Ichijodani, one of medieval Japan’s largest cities. On the outskirts of Fukui, a city of a quarter of a million people in ...