Fukui Castle Ruins, located in Fukui Prefecture, Japan, are the remnants of a once majestic flatland-style castle. Originally built in 1573 by Shibata Katsuie, the castle was later reconstructed by Yūki Hideyasu in 1601. Despite being destroyed in 1871 and further damaged during World War II, the ruins still boast impressive stone foundations, moats, and ramparts. Visitors can explore the site and catch a glimpse of the historical significance of this former stronghold of the Matsudaira clan.