Tsukahara Onsen Kakonoizumi

This hidden hot spring sits on the slopes of Garan-dake, an active volcano, at an elevation of Approx. 800 m. In the large indoor bath and open-air bath, you can enjoy 100% free-flowing, naturally gushing spring water.

Its water is known for being highly acidic, with Japan’s No. 1 iron ion content and No. 2 acidity level and aluminum ion content nationwide. It also stands out as a medicinal bath said to have healing effects for various ailments, drawing not only tourists seeking relaxation but also many visitors for therapeutic bathing, and the hot spring that has been gushing up for 800 years can be called a precious treasure nurtured by Oita Prefecture’s nature.

Another highlight is that you can tour the steaming crater (for a fee): the gradient between the crater’s hell-like scenery with billowing steam and the natural beauty of the plateau stretching into the distance is worth seeing at least once. After your visit, try the steamed eggs, cooked for Approx. 20 hours in crater steam and infused with hot spring minerals.