This stunning, though somewhat unwelcoming, eco-resort in the onsen village of Hoshino, 1km north of Naka-Karuizawa Station, is anything but basic. Modern rooms and villas are positioned around a pond in a beautiful forest setting. All have cypress tubs and are exquisitely furnished on the premise that less is more. Enjoy 24-hour room service from the resort's three restaurants.
You may have to share the decadent onsen with day visitors (¥1300).