Nanki-Shirahama Onsen

Shirahama sits at the tip of a low headland on the Kii Peninsula, and the fastest way to grasp what kind of place it is requires only one image. Walk from the JR Shirahama Station down to the beach, and you will find 620 meters of white sand that is so pale and fine it looks like it was imported. It was, actually, at least in part: the town has periodically replenished the beach with sand shipped from Australia to maintain the color and texture that made Shirarahama Beach famous. The Pacific presses up against it, blue and warm in summer, and behind the beach the hotels stack up the hillside in layers. Then notice the steam rising from places that have nothing to do with the hotels. Shirahama has been a hot spring town for approximately 1,350 years, making it one of the oldest onsen resorts in Japan along with Arima and Dogo.

The water is a sodium chloride and sodium bicarbonate spring, neutral at pH 7, and it flows from the earth at temperatures between 40 and 83 degrees depending on the source. The salt content gives it a mild brine quality on the skin, slightly dense and warm in a way that differs from freshwater baths. At the source spring Miyuki-gensen, the water comes out at 78 degrees and is piped to the outdoor baths called Saki no Yu, which sit on a flat rock shelf at the southern point of the headland. The pools are built directly on the rock, open to the sky, and the Pacific Ocean is right there: not visible in the distance but present, audible, occasionally spraying your face when the swell is up. Saki no Yu is the only surviving bath from Yuzaki's Seven Onsen, a group of springs mentioned in the Man'yoshu, an anthology of Japanese poetry compiled around the year 750.

The overlap of beach and spring creates a town with two moods depending on the season. In August, Shirahama is loud with summer crowds and the beach is packed with umbrellas. In late autumn or winter, the place quiets entirely and what remains is the rock, the water, the old spring sources steaming into the cold air, and the Pacific doing its work on the headland. It is in those quieter months that Saki no Yu is most itself: the rocks slick from sea spray, the water hot, the steam mixing with the salt wind.

The outdoor bath at Saki no Yu charges a small entry fee and provides nothing beyond the pool and the view. There are no gardens, no attendants in uniform, no gift shop visible from the water. You pay, change, walk out onto the rock shelf, lower yourself into the hot sodium spring, and the ocean is in front of you. This is what 1,350 years of knowing what a hot spring is for looks like.