Baths fed directly by a spring that open up to the Tokyo sky
The outdoor hot spring on the top floor provides a breathtaking view of the clipped sky of Tokyo. It offers a unique hot spring experience where you can soak in the "Otemachi Onsen", drawn from 1500 meters below ground while gazing up at the ever-changing sky.
Blessings from the ancient sea
While Otemachi is now filled with skyscrapers, this area was once covered by the sea. As a result, the spring water drawn from the layers containing ancient seawater is rich in minerals.
Impressive spring quality in Tokyo
The amber hot spring is an iodine-sodium-chloride hot spring (hypertonic neutral hot spring). It is suitable for chronic muscle and joint pain and poor circulation and is a rare hot spring in Tokyo that contains iodine.
Subtleties of Tokyo's Sky
The outdoor hot spring is where you can't help but look up at the sky. When you gaze at Tokyo's sky, often obscured by buildings, as though through a telescope, you notice even the slightest subtle changes that escaped your notice.