In the center of Valladolid, on the first floor of an elegant old building overlooking the small Plaza de los Arces. In its own quiet way, it's a well-run hostel with a 20-year history, originally three separate apartments. Rooms are clean, there are 12 of them, and they have a TV. You'll get a bunch of keys, free to mind your own business.
The funny side of Los Arces is the bathrooms: a washbasin of steel, a motorized toilet and a shower cabinet gurgling every time you wash your hands, and with a water level rising critically whenever you take a shower, necessitating a thorough footbath before you're ready. The owner knows the problem and is hopefully contemplating a bathroom renovation. That seems already done in his other Valladolid establishment, Hostal del Val.