Abstract: The bathtub/hot tub is positioned in an opening in the wall of a house. The opening has the same shape as the plan view of the bathtub/hot tub. For a circular bathtub/hot tub, the opening is semicircular. A movable cover in the form of a quarter hollow sphere is pivoted to move from the position where it covers the outer half of the bathtub/hot tub while leaving the inner half inside the house wall accessible. It is movable to an inner position where it seals against the inner portion of the bathtub/hot tub and against the opening in the house wall to leave the bathtub/hot tub accessible from outside of the wall. In either case, the inside of the house is closed against the outside ambient conditions.