Tokyo Somei Onsen Sakura

Tucked into the residential Komagome neighborhood, this day-use onsen draws natural hot-spring water from deep underground, genuinely rare within central Tokyo's 23 wards. Indoor and outdoor baths, a rock garden rotenburo, and a sauna complex provide a complete bathing circuit. The understated modern-Japanese design avoids the theme-park feel of most Tokyo super sento, and the after-bath tatami rest area serves craft beer and light meals.