Tofuku-ji’s tousu, a long wooden hall in Kyoto’s Higashiyama Ward, is the oldest surviving toilet in Japan — built in the early Muromachi period (1336–1573) and preserved today as an Important Cultural Property. Rows of holes line both walls; monks nicknamed it hyakusecchin, the “hundred-person toilet,” and relieved themselves here in required silence as part of Zen training. It’s no longer in use, but visitors can peek inside.