Sawada Koen Rotenburo (Sawada Park Open-Air Bath)

Sawada Koen Rotenburo is a municipally operated public open-air bath set atop a cliff within Sawada Park in Nishina, Nishiizu Town, Shizuoka Prefecture. Perched on a rocky promontory jutting into Suruga Bay, its two small rock baths for men and women (holding four or five bathers each) look out over the sea and horizon, where sightseeing boats and fishing vessels pass below. It is famed above all for the view of the sun sinking into the horizon at dusk, ranking among the finest scenic open-air baths in Izu. There is no lodging; it is a day-use public bathhouse only.

The spring is a sodium-calcium sulfate spring, as confirmed by primary sources from the Nishiizu town office and tourist association, and is said to be good for joint pain and chronic digestive complaints. However, whether the water is free-flowing from the source or recirculated is not stated in any official primary source and remains unconfirmed, and no official source temperature has been published.

Admission is by cooperative fee: 600 yen for adults (12 and over) and 200 yen for children (6 to under 12); town residents pay 400 yen (adults) or 200 yen (65 and over). Hours vary by season: 9:00-19:00 in March-May and September, 9:00-20:00 in June-August, and 9:00-18:00 in October-February (last entry 30 minutes before closing). Closed Wednesdays (the following day if a holiday), with occasional closures during storms or cleaning. Parking is free.