Japan: Dry bath experience at Riraku spa, Hyatt Regency Kyoto

Deep in the bowels of the Hyatt Regency Hotel in Kyoto there is a room containing a pair of large, square baths filled with the dry, fermented powder of the Japanese cypress (hinoki) tree. And me, wearing nothing but black disposable underpants and a white hairnet.

The Riraku spa attendant bows politely and motions for me to enter the right-hand bath, which she has prepared by digging out what looks suspiciously like a shallow grave. I clamber in, lie down and am covered from head to foot with what looks and feels like warm sand.

This is Kosoyoku, a dry bath made from trees grown in Yoshino in Nara Prefecture. It seems there are some things in the hinoki called phytoncides that are supposed to have strong stress-releasing/calming effects.

What isn't in doubt is that, mixed with extracts from other plants, vegetables and fruit, the natural enzymes in this mulch stimulate fermentation and generate heat of 65 to 80 degrees. Which means it's bloody warm in here – an effect compounded when the attendant asks if I want to take the extra step and have the sand cover my face, too. Some people, she says, find it too claustrophobic.

I take the plunge, which consists of having another hairnet placed over my face and sand piled on top of that, leaving just the nose and mouth free.

The Hyatt Regency sits behind a big stand of bamboo in Higashiyama Shichijo, a verdant suburb of Kyoto which also boasts the Kyoto National Museum and the impressive Sanjusangen-do Temple with its 1000 life-size statues.

The hotel, which opened in 2006, isn't much to look at from the outside but this low-key first impression is in stark contrast to the interior, which was designed by Takashi Sugimoto from Super Potato, an eminent Japanese interior design company.