Onsen: dive into another side of Japan

I’m hovering starkers beside a hot spring, or onsen, in a faded resort in southern Japan, while the Japanese grandmother standing naked next to me explains the form for the steaming pool I am about to enter. It’s an open-air mud hot spring, known as a doroyu and quite unusual, even in Japan, where the hyperactive geology means onsen of all kinds spring up — literally — everywhere.

I love a scalding bath, so it was perhaps inevitable that I should love onsen from the moment I first dipped a toe in one many years ago, close to Mt Fuji on a day trip from Tokyo. The ritual of washing before bathing, soaking in piping hot waters, the tranquillity, the beautiful settings, the deep sense of relaxation — I simply can’t get enough. Which is how I ended up in the city of Beppu — my first stop on a circumnavigation of the island of Kyushu in search of hot springs.