Onsen and Spa in Osaka: Spa World, Solaniwa, City Sento, and the Real Hot Springs an Hour Away

Osaka sits on a plain, not a volcano, so the city's baths are heated and mineralised rather than drawn from the ground, with a few exceptions that pump from deep wells. That does not make them worse for a first bath: the etiquette, the outdoor tubs, the saunas and the post-bath meal are the same, and the complexes here are the largest in Japan. For a real geothermal spring you go to Arima in the Rokko mountains behind Kobe, an hour away, or further to Kinosaki on the Sea of Japan.

Spa World, next to Tsutenkaku in Shinsekai, has European and Asian themed floors that swap between men and women monthly, a rooftop pool zone in swimsuits for families, and stays open almost round the clock; it is the most tourist-friendly and the least traditional. Solaniwa Onsen at Osaka Bay Tower is an Edo-themed complex with yukata rental, a garden of outdoor tubs and restaurants, more atmospheric and pricier. Nobeha no Yu in Tsuruhashi and the Naniwa no Yu in the north are the local-standard super sento, cheaper and less themed. Expect 1,500 to 3,000 yen.

Osaka still has several hundred sento, the public baths that predate home bathrooms, at around 500 to 600 yen. They are small, hot, fast and full of regulars, and the one near your hotel is the most Japanese hour you can have for the price. Bring a small towel or buy one; wash sitting at the taps before entering the tub; no swimwear; hair up; phones away. The Osaka nightlife guide notes the ones that suit a late evening.

The big complexes ban visible tattoos, and Spa World checks at the desk. Cover stickers of about 10 by 15 cm are sold at chemists and inside some spas and are accepted for small pieces. Small sento often do not care; ask at the counter. Private family baths (kashikiri) at the complexes and at Arima's ryokan are the reliable answer for large tattoos, booked by the hour.

Arima, reached by Hankyu or Hanshin to Kobe then bus, or a direct highway bus from Osaka's Umeda in about an hour, has two waters: kinsen, the iron-rich brown gold spring, and ginsen, the clear silver one, in two public bathhouses and a street of ryokan that open for day bathing. It is Japan's oldest recorded onsen town. Kinosaki, two and a half hours by limited express, is the yukata-and-clogs town with seven public baths and is an overnight, not a day trip. Tours to Arima from Osaka combine it with Kobe beef for lunch; the Kobe day trip page has the route.