10 Onsen in Izu and Atami, Handpicked by Our Editors

Editors' comment

Three private baths dotted around the grounds each have a different character: a tub carved from a huge boulder, a Japanese-style bath accented with bamboo, and a quiet one enclosed by rock. All are fed straight from the source, never recirculated, with no reservation and no charge — enter as many times as you like when one is free. Without a washing area, there is nothing to do but soak. The main bathhouse draws on its own source, lined with a hinoki indoor bath, a ceramic urn bath, a hot-water cascade, and a rock-built open-air bath; the alkaline calcium-sodium sulfate spring feels gentle on the skin. You make your way through the grounds — hills, fields, a pond, a stream — moving from one tub to the next. A sauna is also on hand.

Editors' comment

Yoshina Onsen, said to have been discovered in the Nara period, ranks among the oldest sources in Izu. It is a colorless, alkaline onsen with a smoothness that seems to glide over the skin. Across the roughly 36,000-tsubo (about 119,000 sqm) grounds, bathhouses of different character are scattered. The open-air bath Kajika-no-Yu, alternating between men and women, pairs a tub of Izu stone with hinoki edging, stone and wood textures set side by side. The private open-air bath Kodakara-no-Yu, reserved for guests staying overnight, sits behind the entrance building, a roofed space where you can still feel the outside air. Tomo-no-Yu in the west wing is a semi-open-air bath for one or two. The detached rooms along the clear stream and the tatami-and-bed rooms also come with their own open-air baths. At this inn you can trace the same source from place to place while listening to the murmur of the river.

Editors' comment

Standing on a hill in the Atagawa Highlands, the main bathhouse’s open-air bath is a single deep tub, 125 cm (about 49 in) deep. Sit on the bench inside and the water reaches your shoulders; stand and it comes up to your chest. Suspended by the water’s buoyancy, you face an unobstructed view of the Pacific and the Izu Islands. It is a design that only works with a deep tub — one where the water’s surface and the sea appear to merge into a single plane. All 26 rooms have a terrace and their own onsen open-air bath, so you can soak in the waters of Atagawa at any hour, from the glow of dawn to a sky full of stars.

Editors' comment

On the seventh floor, the panoramic main bathhouse leads from a glass-walled indoor bath out to an infinity open-air bath, where the water’s surface appears to merge directly with Sagami Bay. The sulfate-and-chloride onsen feels gentle on the skin, and the warmth tends to linger even after you step out. By day the sea glitters with light; by night the water’s surface ripples under the moon — the view keeps changing by the hour. Every room also has its own onsen open-air bath on the balcony, where you can soak at any time you like, unseen. The main bathhouse also has a sauna and a cold plunge. Here, the distance between the sea and the onsen is unusually close.

Editors' comment

If the lamp by the sign is lit, you can open the door and lock it from inside. Seven private baths, no reservation or extra charge required. A rock bath facing a bamboo grove, a vermilion ceramic urn bath, an octagonal tub, a bath enclosed by clay walls — each differs in shape and in how it is enclosed. All are filled with the onsen of Shuzenji, said to be among the oldest in Izu, an alkaline simple onsen with a soft touch on the skin. The main bathhouse on the top floor has an open-air bath of stone and hinoki, open both night and morning. Few inns let you confirm the same source again and again, each time in a different vessel.

Editors' comment

At the top-floor open-air bath, Sora, the line between sea and sky disappears at the tub’s edge. It is filled with a sodium-calcium chloride spring; because of the salt it holds, this onsen retains heat well, and warmth lingers at the body’s core long after you step out. That mineral quality is a large part of why the open-air bath stays warm even in the sea breeze. From the panoramic bathhouses Umi and Kamome you can take in the whole of the Pacific, with the view changing between sunrise and sunset. The onsen-only building, Yukkura, stays open through the night, so you can return to the bath again and again beneath the sound of waves and a sky full of stars. Every room faces the sea, and each room’s own open-air bath draws directly from the source.

Editors' comment

Standing along the Kano River in Yugashima, this inn is registered as a tangible cultural property. Its calcium-sodium sulfate spring is fed straight from the source, never recirculated, and thanks to its high moisture-retaining quality it has long been known as an onsen good for the skin. The bathhouses each have their own character. Tengu-no-Yu combines an open-air bath overlooking the mountains of Izu and the Kano River with a cave bath thick with steam. Hoshi-no-Yu is an open, tree-lined open-air bath where the murmur of the mountain stream never stops. Bettei Shakunage has both a private open-air bath and an indoor bath, letting you take in the same source away from other guests' eyes. Several saunas are also on hand.

Editors' comment

At the heart of this inn is the fact that every room’s open-air bath is a natural onsen fed straight from the source, never recirculated. The tubs are hinoki and Shigaraki pottery. With no one else around, you can sink into the water as long as you like, whether just after arrival or late at night. Ahead lies Sagami Bay and the town of Atami. The water is a sodium-calcium chloride-sulfate spring, a type known for warming the body to its core. The main bathhouse has a panoramic open-air bath open to the sea breeze and a carbonated bath, along with a sauna and a cold plunge.

Editors' comment

The four private baths scattered through the inn are all fed straight from the source, never recirculated. A round hinoki tub, an open-air bath looking onto the forest, a reclining bath, and a hotter bath where you can adjust the temperature yourself — each is set up differently. No reservation, no charge. Check the sign on the door, and for that stretch of time the bath is yours alone. They are open around the clock, so it makes no difference whether you go at midnight or at dawn. The indoor bath in the main bathhouse faces the Katsuragawa River, where you can soak in an alkaline simple onsen while listening to the sound of the water. The garden open-air bath changes character between day and night, so a single stay lets you see two different faces of the same view.

Editors' comment

The waters of Kidachi-no-Yu, flowing in Yugashima for 800 years, fill the tubs fed straight from the source, never recirculated. It is a simple onsen with a soft touch, and it is interesting how it feels different from place to place. The cave bath enclosed by rock walls holds a dark, close air; the open-air bath facing the mountain stream offers the sound of water and an open view; and there is also a spacious indoor bath. You can move back and forth between them, comparing the same source. The open-air bath in the room is made of Shigaraki pottery, set on a private terrace looking out over the forests of Amagi, where you can soak without watching the clock. Private baths are also available, and day-use bathing is accepted. A sauna is on hand as well.