The term is derived from the name of the town of Spa, Belgium, whose name is known back to Roman times.
Drug rehabilitation (often drug rehab or just REHAB) is a term for the processes of medical or psychotherapeutic treatment, for dependency on psychoactive substances such as alcohol, prescription drugs, and street drugs such as cocaine, heroin or amphetamines.
The hotel is often 2 - 4 stories high and usually has a more personal atmosphere.
It's usually located near affordable attractions, major intersections and convenient to public transportation. Most will not have a restaurant on site but are usually within walking distance to some good low-priced dining.
Public access, past certain hours, may be restricted.