Babington House, Gloucestershire
This West Country hotel, an outpost of London members' club Soho House, boasts the group's original Cowshed spa. Open to non-members, it has a distinctly rustic feel, with exposed stone walls, wooden floorboards, sisal matting, florally upholstered sofas and old leather armchairs. There are areas to soak and relax as well as a sitting room which opens on to a Victorian garden where you can slump with a cup of tea.
Babington House, Babington, near Frome, Somerset BA11 3RW (01373 812266; babingtonhouse.co.uk ). Doubles start at £195, room only. Treatments start at £38.
The Gleneagles Hotel, Perthshire
This 1920s country pile recently underwent an £18m face lift, which nipped and tucked it in all the right places to bring Scotland's most eminent five-star hotel up to date. Among the innovations was the introduction of an Espa spa, at which guests are encouraged to linger in heated rooms and pools. The décor is as decadent as the treatments: wood and gold panels, berry-coloured chairs, a dusky Asian-inspired relaxation room and a breezy courtyard garden. Furthermore, the Deseo spa café serves everything from fruit salad to an "indulgence bento box" packed with Scottish salmon, crab, and chocolate pots.
The Gleneagles Hotel, Auchterarder, Perthshire, Scotland PH3 1NF (01764 662231; gleneagles.com ). Doubles start at £199, including breakfast. Treatments start at £35.
The Dorchester, London
The Dorchester Spa evokes old-fashioned Hollywood glamour with rose-tinted mirrors, locker keys on faux-pearl bracelets and a boudoir-style "Spatisserie" where you can quaff champagne and eat cakes after your treatment. The virtuous can work their way through dried fruit and nuts and a staggering list of teas in the decadent relaxation room – a vision of inky blue velvet and cream leather, mirrors, day beds and winged armchairs.
The Dorchester Spa, Park Lane, London W1K 1QA (020-7319 7109; thedorchester.com ). Doubles start at £347, including breakfast. Treatments start at £55.
This gracious 19th-century manor house hotel might not win awards for cutting-edge design, but its health spa frequently picks up accolades for its Elemis treatments and extensive facilities. In addition to fitness machines, a thermal area and pool, there's a serene spa garden complete with chemical-free pool, 1930s Italian Cruiser chairs, hot tubs, sauna and café.
Foxhills, Longcross Road, Ottershaw, Surrey KT16 0EL (01932 872050; foxhills.co.uk ). Doubles start at £140, including breakfast. Treatments start at £35.
Sofitel St James, London
Dark wood and rich colours prevail in the drawing-room decor here. A "spa butler" guides guests through the experience, which could start with a Turkish hammam and end with a "pint and pedicure", tea and macaroons, or supine with a cashmere blanket in the relaxation room.
So Spa at Sofitel St James, 6 Waterloo Place, London SW1Y 4AN (020-7747 2200; sofitelstjames.com ). Doubles start at £188, room only. Treatments start at £45.
Rockliffe Hall County, Durham
The newest luxury resort to open in the North East is set in stunning countryside. No less impressive is the spa, which features organic Ila products, a salt room, an igloo and a Sleep Retreat with sound-wave therapy relaxation beds. To revive you, a "spa butler" is also on hand.
Rockliffe Hall, Hurworth-on-Tees, Darlington, County Durham DL2 DU (01325 729999; rockliffehall.com ). Doubles start at £270, including breakfast. Treatments start at £35.