Mount Tsukuba Keisei Hotel

Mount Tsukuba Keisei Hotel sits partway up the mountain, and its baths look out over the Kanto plain: city lights and a wide starry sky at night, with sunrise over Lake Kasumigaura from the east-facing side. From the guest rooms, clear days bring Tokyo's skyline, the Skytree, and even Mount Fuji into view. The bathing area is split into a north and south side, each with its own indoor and open-air tub, and the two sides swap between men and women in the morning and evening. The water is a strongly alkaline simple spring, smooth on the skin rather than mineral-heavy. A small rental bath can be booked for an hour late at night or early in the morning for those who want the view to themselves.