“Thirsty?” the flight attendant asked as she handed me a blue bottle. I twisted the cap and sipped the crisp, slightly acidic water. One look at the label, Spa Reine, and I wondered whether the advertising gods were tracking me. Spa. That’s where I was headed.

No, not to the spa — to the Belgian town.

In the town of Spa, Belgium, La Geronstere still spouts sulfurous spring water that is recommended as a treatment for respiratory ailments.
Sylvie Bigar / Washington Post News Service
In the town of Spa, Belgium, La Geronstere still spouts sulfurous spring water that is recommended as a treatment for respiratory ailments.

Last year, after several grueling weeks spent juggling teenagers, dogs, and deadlines, I sat at my computer, bent on planning a spa break. Instead, I stumbled on that town in Belgium where, I learned, the common noun originated. A few clicks and I was hooked.

In September, I flew to Brussels and took the train for an easy two-hour ride to Spa (pop. 10,000), near Liege within the Ardennes forest, to discover where it all started.

Lulled by the rhythm of the rails, I admired the late summer light streaming through the dense, peaceful woods, but I knew those trees had been the site of one of the fiercest military battles of World War II. The Battle of the Bulge, Hitler’s last major offensive against the Allies, claimed 19,000 American lives in just a few weeks.

"Thousands of soldiers are buried in military cemeteries in the area," said Gaëtan Plein, a guide and raconteur, the next day as we strolled through the quaint town center.

The Pouhon Pierre le Grand dates to the 19th century and serves as a monument to Peter I. It also houses the main town spring.
Library of Congress / Library of Congress
The Pouhon Pierre le Grand dates to the 19th century and serves as a monument to Peter I. It also houses the main town spring.

Some say there are 25 springs, while others count as many as 300 sprinkled throughout the rolling hills. Their medicinal properties were already known locally in the 16th century, but when Czar Peter I of Russia — that’s Peter the Great — arrived for a month-long stay in 1717 at the recommendation of his doctor and left seemingly cured of his liver ailment, he ignited the interest of aristocrats throughout Europe and Russia. Suddenly, Spa was the place to be.

"At the time," said Marie-Christine Schils, the curator of the Museum of Spa, "doctors weren’t sure how the water helped, but they prescribed it to combat anemia, depression, and even infertility."

Over the next decades, noble gentlemen and ladies, accompanied by their massive entourages, flocked to town to drink the healing waters. A 1734 guidebook of the springs would find its way to Marie Antoinette’s library at Versailles.

To accommodate and entertain these travelers, who often stayed for weeks at a time, hotels and boardinghouses sprouted, promenades were constructed, and the first casino was built. (That would serve as a recreation center for the First United States Army in 1945.)

"Upon returning to England," Schils said, "English doctors appended the name Spa to local springs with similar properties, such as Scarborough Spa," and that’s how the name became generic.

In the 19th century, Spa was stylish. European artists such as J.M.W. Turner and Gustave Courbet and writers such as Alexandre Dumas and Victor Hugo visited. Even the American writer James Fenimore Cooper made the trip, as did the new bourgeois crowd. Bathing in the mineral water became fashionable, and the town reinvented itself as a "thermal city" not only focused on health but also on the new concept of well-being.

"Taking the waters was medicinal, yes," Schils said, "but it also became social. It was important to see and be seen."

Walking was part of the regimen recommended by the local doctors in the 18th century, so we went to the Parc de Sept Heures, one of three public landscaped parks. Inaugurated in 1758, the park is dotted with Belle Epoque constructions, often melding wrought iron and glass. There are pavilions, kiosks and a covered promenade where patients were instructed to stroll several times a day.

I was sorry to miss the weekly Sunday flea market, but all this walking made me thirsty, so we went into Pouhon Pierre le Grand, a newly restored octagonal pavilion dating to the 19th century that serves as a monument to Peter I and also houses the main town spring. Under the towering glass rotunda, I finally sipped the sparkling mineral water. Crisp, slightly acidic with a hint of sulfur, it felt invigorating.

The next day, so that I might understand the underground path of that magical water, Plein drove me along country roads lined with historical mansions and villas to the high plateau that sits above the main water table. We followed marked trails — the area counts 200 of them — through meadows and groves toward the Forest and Water Museum of the Bérinzenne Domain.

"Here, it rains an average of 230 days a year," Plein said as we watched a presentation about the decades-long process that starts with rain and ends at the springs through layers of moss, peat, clay, sand, and quartz schists. Later, we hiked the four-mile Promenade des Artistes through the golden forest and along a river. Lunch on the terrace of La source de la Geronstere, near the spring of the same name, was restorative and delicious.

The next morning, I headed to the Laundry Museum, unsure of what fell within that category. But Paul Jehin, the co-founder and a passionate sociologist, explained his mission simply: "We wanted to pay tribute to the beehive of unsung local workers who labored for decades behind the scenes, while their employers, most often foreigners, strolled, partied, and took the waters."

At the Laundry Museum, artifacts and photos such as this 1927 image of the staff of the Belle-Vue Hotel, one of the greatest hotels of the day, depict life behind the scenes in the resort town.
Laundry Museum / Laundry Museum
At the Laundry Museum, artifacts and photos such as this 1927 image of the staff of the Belle-Vue Hotel, one of the greatest hotels of the day, depict life behind the scenes in the resort town.

Spa, with its hotels and casinos, swarmed with coachmen and cleaners, waiters, cooks, and the laundresses who organized themselves in small ateliers. Jehin has amassed a treasure trove of objects and machinery: dozens of flatirons spanning several centuries; soap powder boxes with their first advertisements; fine sheets; ancient articles of clothing; even the first mechanical washing machines.

Finally, I was ready for the physical part of my research. The Renaissance-style Thermes building, dating to 1868, is no longer in use, so I hopped onto the nearby funicular that leads up the hill to Les Thermes de Spa, a modern complex surrounded by nature. There, I chose to take a bath in one of the antique copper tubs filled with heated mineral water from the Marie Henriette spring.

An uncountable number of bubbles appeared on my skin, creating a deliciously relaxing aquatic shudder. A shower massage soothed my sore muscles. Later, I went swimming in the gigantic pool.

Surrounded by the forest, I fell asleep on a lounge chair and dreamt of a czar taking the waters next to me.

Museum of Spa: Spavillaroyale.be (in French) or 011-328-777-4486.

Les Thermes de Spa: Thermesdespa.com or 011-328-777-2560.

Laundry Museum: spatourisme.be/en/laundry-museum or 011-328-777-1418.

General information: Spatourisme.be/en