Tokyo Nerima City
Toshimaen Niwa no Yu in Mukoyama, Nerima-ku, Tokyo, is an 'otherworldly escape in the city' surrounded by a 1,200 tsubo Japanese garden. The outdoor Finnish sauna in the garden features 600 kg of sauna stones and an automatic löyly system, promoting vigorous sweating with the scent of wood. The mist-type steam sauna is set at 45-50°C, gently warming the body with humid heat. For cooling, there is a deep cold plunge bath with a garden view, 140 cm deep, enhancing the 'totonou' experience quietly with the outdoor environment. The water is a natural hot spring rising from 1,445 meters underground, with both open-air and indoor baths offering views of the garden.
Utilizes natural hot spring water pumped from 1,445 meters underground. The spring quality includes ions such as sodium, calcium, and iron, with both indoor and open-air baths available, allowing for a relaxing soak while enjoying the garden view.
A sauna hut richly lined with fragrant natural woods such as red cedar. You can sit on the relatively wide benches and warm up slowly. The uppermost area has a low ceiling, allowing you to experience intense steam and heat pouring down like in authentic saunas. A quiet sauna with dim, warm lighting. Renovated in April 2024, it now features automatic löyly every 15 minutes. Sauna mats are available outside the sauna room. No TV.
A low-temperature, high-humidity type that warms the floor, walls, and seats, allowing heat to gently radiate. Recreates the steam bath of ancient Roman baths, promoting comfortable sweating. Located in the sauna area of the bathing zone.
Enjoy views of snowy scenery that enhance the feeling of being in Finland. The adjacent bucket shower is recommended for rinsing before entering. This deep cold plunge bath lets you soak up to your shoulders, causing rapid vasoconstriction and promoting circulation.
A special-design cold plunge bath inspired by the Finnish practice of cutting a hole in a frozen lake. It cools a heated body from feet to head in one go. Depth 140cm. An overhead bucket shower is also installed.
Irregular Holidays
Visited by the Editor-in-Chief
The Editor-in-Chief visited in person in December 2025
A First in My Life: Taking a Numbered Ticket at an Onsen
Read the full review
Tokyo
A Kanto-area sauna hotel on a grand scale, with 4 types of sauna and 4 types of cold plunge bath
Tokyo
One of Kanto's largest spas where Tokyo's only "100 Famous Waters" spring and a natural hot spring shine
Tokyo
A city oasis that soothes both body and mind with beautifying natural hot springs and authentic sauna
JAPAN'S FINEST ONSEN & SAUNA
The Finest Onsen & Sauna in Japan
57 SELECTIONS
Most of what we surveyed never even made it onto this site. This book is a further cut from what did. Our editor bathed in every onsen and sauna in it, and wrote only what they confirmed on the ground.
