Hot water still rises from the ground in Bath at about 45 degrees. At Thermae Bath Spa it is cooled to roughly 34, and then you get in. In winter, with cold air on your shoulders and steam lifting off the surface, it is one of the great simple pleasures in Britain.
The spa describes itself as Britain's original natural thermal spa, fed by the only naturally hot, mineral-rich springs in the UK. That claim is the reason to come rather than visit any ordinary pool. The Romans knew this place as Aquae Sulis and built their baths around the same springs, and that long habit of bathing here gives the experience a weight that a hotel spa cannot borrow.
The open-air rooftop pool is the centrepiece. It is open by day or by night, and the strongest argument is for the dark. Warm water below, a cold sky above and the lit city beyond the edge make for a very particular hour. A rooftop pool in winter is the whole point, and the lower the temperature outside, the better it works.
Then there is the Cross Bath, a separate oval open-air thermal bath. Its site was revered by the Celts for the goddess Sul and is recognised as an official sacred site. The scale is far more intimate than the main spa, and it can be taken over for small private parties, which suits a birthday or a gathering of close friends who want the bath to themselves.
The spa sits at the Hetling Pump Room on Hot Bath Street, 200 yards from Bath Abbey, so it fits easily into a day of walking the city. Treat the bathing as the main event and arrange the rest around it. A morning in the streets and the Abbey, a late lunch and an evening in the water is a well-judged order, and it leaves you tired in the right way for the train home.
Note the age limits before you book. The minimum age is 16 for the spa and 18 for treatments. Check the spa's website for sessions and booking, and give yourself time to move slowly. Nothing about hot spring water rewards hurry.
Best for A cold, clear weekday.
