Mild and low in dissolved minerals. Usually clear and gentle on the skin, which is why these baths are often recommended for first-timers.
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
Clear water with a faintly bitter taste. Known for holding heat.
Contains trace radon that leaves the water quickly. Also called radium or radon springs.
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.