Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
Turns reddish brown as the iron meets air. The water is clear at the source.
The classic rotten-egg smell and milky white water. It can tarnish silver jewellery, so take it off.
40.4184, 140.6173 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.