Osaka Castle is one of Japan's largest, covering over 100ha. The 30m stone walls and 90m moat are impressive. Why was such a huge castle needed? Learn about the powerful daimyo who moved history.

WAKAYAMA—A rare event to explore the underwater world of Wakayama Castle’s moat took place here on Oct. 5 as volunteers and city officials lowered the water level, revealing a hidden ecosystem.

HIROSAKI, Aomori -- Snow-covered cherry blossom trees and a castle moat in this northern Japan city are currently lit up in pink in the evenings, to the delight of visitors. The "Fuyu ni Saku ...