Tamagawa Onsen — Showa Retro Bathhouse

pH 10 slippery water and a 1950s classroom — a retro onsen bathhouse in the Saitama hills

Tamagawa Onsen is a day spa in the hills of Tokigawa, Saitama, an hour and a half or so by car from central Tokyo, whose full name — “Showa Retro Onsen Sento Tamagawa Onsen” — says it all: the whole place recreates the 1950s. Beyond an entrance lined with old enamel signs, a red postbox and a penny-sweet shop, a tatami-floored “classroom” serves as the lounge, and at night warm bulbs give it the air of a film set. What really made it famous, though, is the water: the pH 10.1 alkaline simple spring is among the most alkaline in Kanto, so slippery it feels as if you had soaped yourself, and besides tubs heated from the 26.6 °C source there is a “gensen-buro” of unheated source water that draws onsen enthusiasts from afar. The rotenburo has rock and barrel tubs; sauna, cold plunge, carbonated bath and bedrock bath are included, and admission is ¥980 on weekdays and ¥1,180 at weekends — though weekend and holiday mornings from 5 a.m. cost ¥780 and evenings after 20:00 ¥580, so picking your slot saves a lot. By rail it is a little awkward — 2.5 km from Myokaku Station on the Hachiko line, or a town bus from Ogawamachi on the Tobu Tojo line — but that is exactly why it has a rural ease no city super-sento can match. Open daily except a few maintenance days a year.

Tips & cautions

- Weekdays 10:00–22:00, weekends & holidays 5:00–22:00 (last entry 21:30). Best value: weekend mornings 5–8 a.m. (¥780) and after 20:00 (¥580).

- Very slippery high-alkaline water — tub floors and wash areas are slick; mind children and the elderly.

- The unheated source tub is in the 26 °C range — refreshing in summer; alternate with heated tubs.

- Loungewear required for the bedrock bath — rent it.

- Tattoos: no published rule — the private family bath is an alternative; ask in advance.

- Weekend afternoons are busy with families; classroom lounge seats go fast.

- Public transport is sparse — check bus times, or taxi from Myokaku Station.

- Tokigawa is a “town of wood” — combine with local woodwork cafés and a riverside stroll.

Getting there

2.5 km from Myokaku Station (JR Hachiko line; 30 min on foot or 5 min by taxi), or Tokigawa town bus from Ogawamachi / Musashi-Ranzan (Tobu Tojo line) to “Juodo-mae”, then 11 min on foot (Tamagawa 3700, Tokigawa, Saitama). By car ~25 min from Higashi-Matsuyama IC (Kan-etsu Expressway) or ~30 min from Sakado-nishi smart IC; 110 free spaces. Tel. 0493-65-4977.