Nishiyama Onsen Keiunkan holds the Guinness World Record for the longest continually operating hotel in the world, and second longest running business, losing out (just barely) to a Japanese construction company.
How old, you ask? 1,320 years. No, that's not a typo.
For 1320 years, this traditional ryokan has been operating since its founding in the year 705. During those thirteen centuries(!), Keiunkan has hosted the likes of emperors, shoguns, daimyos, and all manner of Japanese noblepersons; from the highest to the lowest, the divine to the mundane, all the way down to a lowly ashigaru, such as myself, and my family, who had the privilege of staying here this week.
Situated in the stunning Hayakawa valley, this storied, four-storey hot spring retreat boasts multiple public and private, indoor and outdoor baths, on the first and fourth floors; the full ryokan experience (tatami mats, traditional futon for sleeping on the floor); traditional kaiseki dining with a la carte options; and an unrivaled aesthetic - misty mountains, lush forests, and a rushing river, all viewable from your large private suite which, in our case, included three rooms, in addition to the private restroom and ofuro.
The baths themselves are gorgeous and well-maintained. Some baths are public and gender-segregated, and flip their schedules for which gender is allowed to use them at which time, in twelve hour increments (i.e. one bath will allow men from 8am-8pm, and women from 8pm-8am).