The world is full of spa towns. But the original Spa is deep in the Ardennnes.
The little town was once a glittering place where royalty and aristocrats went to cure their illnesses by soaking in copper bathtubs and drinking the almost undrinkable water that trickled out of several springs. Spa was known to the Romans, who called it Aquae Spadanae. Its fame began to spread across Europe in the 1560s when a Ličge doctor published a pamphlet praising the health-giving water. The town grew into a fashionable resort in the 18th century with elegant hotels, baths, parks, restaurants and casinos.
The famous guests included Tsar Peter the Great, who gave his name to the source Pouhon Pierre-le-Grand in the town centre. The town was occupied by German generals during the First World War, when Kaiser Wilhelm took over a former school as his campaign headquarters. But the resort in the hills lost almost all its glamour in the 20th century. It became a sad old town in the rainy Ardennes full of abandoned hotels, rusting fountains and dilapidated Art Nouveau villas.
The town is now being gently nursed back to health, aided by the opening of a Radisson Blu Palace hotel, a modern funicular and the hilltop wellness centre Les Thermes de Spa where you can soak in steamy pools with views of the Ardennes woods.

https://www.brusselstimes.com/art-cu...e-original-spa

Spa in Belgium:
https://nl.wikipedia.org/wiki/Spa_(stad)
https://www.thermesdespa.com/geschie...ermen-van-spa/
https://en.wikipedia.org/wiki/Spa,_Belgium
https://ard.bmj.com/content/61/3/273.full#R2