Photo: Soica2001 (talk) · Public domain · Wikimedia Commons

Osorezan Onsen

Aomori · 恐山温泉

Osorezan Onsen is a hot spring town in Aomori, Japan. The water leaves the ground at 70–90°C, hot enough that it has to be cooled before anyone can get in. It measures pH 1.89–2.71 — strongly acidic, the kind that stings on a cut. Officially the water is classed as chloride spring, iron spring, acidic spring and sulfur spring. 1 inns take visitors here.

Getting there

From Tokyoabout 5½ h

CarNot needed

JR PassCovers the train

Train to Shimokita Station (JR)
Local bus, about 40 min

Fly into Haneda or Narita. Times are rough estimates worked out from station locations, not a timetable — check the exact route on Google Maps.

Chloride springIron springAcidic springSulfur spring

The water here

Chloride spring 塩化物泉

Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.

Iron spring 含鉄泉

Turns reddish brown as the iron meets air. The water is clear at the source.

Acidic spring 酸性泉

Strongly acidic, sometimes below pH 2. It stings on cuts and is not for long soaks.

Sulfur spring 硫黄泉

The classic rotten-egg smell and milky white water. It can tarnish silver jewellery, so take it off.

Things to see nearby

Lake UsoriLake · 1.2 km

Bodai-ji TempleTemple · 0.1 km

Mount OzukushiMountain · 4.3 km

Kamafuseyama Ski ResortSki area · 7.7 km Entsū-ji TempleTemple · 11 km

Places from Wikidata, photographs from Wikimedia Commons. Distances are in a straight line from the town.

With tattoos

Many public baths still turn away visible tattoos, and the rule is set by each bath, not by the town. The reliable way round it is to bathe privately: a room with its own open-air bath, or an inn with a private bath you can book for yourselves.

Inns with a private bath — Aomori