As I gaze out the window at perfectly straight rows of green vines rising up the gently rolling hills, I picture knights on horseback riding toward the medieval castles at the top and towering over the Rhine River. I’m sitting in a comfortable seat on a train at a table across from travel companions — a small group of journalists — when a waiter stops by, asking if we’d like something to eat or drink. A cold beer and hot chili arrive a few minutes later. This is so much better than being in an uncomfortable airplane seat, staring at the clouds after waiting in multiple lines, emptying electronics from my backpack, dumping my water, and removing my coat and shoes. On top of it, the train I’m traveling on is releasing significantly fewer carbon emissions. Though this mode takes more time to arrive at my destinations, it’s much easier to get to small, historic towns that aren’t readily accessible by airplanes.

I’m traveling along a small portion of the European Route of Historic Thermal Towns, one of more than 45 routes certified by the Council of Europe.

We begin the trip in Spa, Belgium (yes, the actual name of the city), one of 11 towns in seven countries that, in 2021, were designated “transnational serial” World Heritage Sites by UNESCO, known as The Great Spa Towns of Europe. Spa’s thermal springs were first documented nearly 2,000 years ago and became known as places of relaxation around the world. Only two hours by train from Brussels, this favorite of Czar Peter the Great quickly becomes a favorite of mine.

Strolling through the streets of this town of 10,000 residents, I see bakeries serving meringue cookies, cheese shops, and cafes. Locals offer a friendly “bonjour” as they pass. 10 colorful statues of Pierrot (Peter, as in the Great), the city’s symbol of a jumping clown and mascot of the bottled water originating here, dot the streets. And the casino, a staple of historic spa towns, sits in the center of it all.

After walking around, we head up the funicular to Thermes de Spa. Three types of water feed the spa: one for drinking, one for pools, and one for both drinking and spa treatments. While all of the water originating directly from the thermal springs tastes of salt and sulfur — the result of underground mineral concentrations— these flavors change depending on what spring the water comes from. Some even offer a bit of unexpected natural carbonation.

Exiting the locker room to the thermal spaces, we luxuriate in pools of varying temperatures, from polar-plunge cold to aah, I’m never getting out. After trying out every pool (indoor and outdoor), shower, and sauna, and relaxing with a post-soak beer, we head to Hôtel La Reine to change before dinner at the property’s Michelin-listed restaurant, La Cour de la Reine.

The following morning, a short walk leads us to the train station for the 4.5-hour ride to Bad Ems, Germany. We’re using Interrail Flexi Global Passes, which allow us a certain number of days of unlimited travel by train in two or more countries within one month. We have the seven-day flexi passes, but you can get different time periods for these, from four to 15 days. With a few exceptions, this pass lets us travel on almost all trains in Europe without reservations, offering flexibility when a train is late or plans change. (Interrail passes are for citizens and legal residents of European countries; for everyone else, Eurail passes do the same thing.) We soon encounter another benefit.

Two and a half hours into our trip, we stop in Cologne, Germany, to change trains. Our 40-minute connection time gives us a window for a quick visit to the Cologne Cathedral. Rising high directly across the street from the main train station, the 775-year-old architectural masterpiece is a UNESCO World Heritage Site and at one time, the tallest building in the world. We don’t have time to fully explore it (that could take the better part of a day), but we do get a chance to admire its beauty on the outside and in. One fellow traveler watches our bags, though we could have also used the automated luggage storage system at the train station. And if we didn’t have a schedule to keep, we could even hop on a later train and explore more.

We arrive in Bad Ems in the early afternoon. Sometimes called the “Imperial Spa,” Bad Ems was one of Germany’s most famous bathing resorts in the 17th and 18th centuries. A destination where royalty, politicians, musicians, and writers flocked, it became a place to see and be seen. Though we have no celebrity sightings while walking along the river on this rainy afternoon, our local guide points out the many buildings lining the waterfront that date from the start of a boom time from the 1820s to 1860s. Soon after the railway was built in 1858, posters advertised, “Depart Paris at 9 p.m. and arrive in Bad Ems at 9 a.m.”

Continuing our walk along the historic colonnade — another hallmark of historic thermal towns — we find the casino, Spa Theatre, and Marble Hall. Painted in a creamy yellow, the building has gold chandeliers hanging from deep-green silks. Elaborate decorative tiles cover the ceiling and walls, giving visitors the feeling that the great composer Offenbach might step onto the stage at the front of the room at any moment.

While a few of people in our group choose to take a ride on the town’s funicular, most of us decide a warm thermal bath is the perfect follow-up to an interesting yet cold and rainy walking tour. Heading back to the modern Emser ThermenHotel, with rooms decorated in royal blue, we pass the Old Town Hall and its arc of 12 bells hanging atop and ringing a selection of tunes three times per day.

My travel companions and I meet in the hotel’s thermal pools, but not before passing an area of fully nude bathers filling the large entry area holding saunas, steam rooms, showers, and lockers — a reminder that coed bathing is common in Germany and Austria (nudity is often a requirement to use some areas of facilities). Trying to play it cool, I head to the shower area, and after a quick rinse, I explore the many thermal pools bubbling up in different patterns. Outdoor whirlpools wind us in circles; big, massaging bubbles come from below our backs and bums; and thermal rain showers fall from deep-blue lights. We finally head outdoors to the dry sauna sitting along the riverbank. While the pools require clothing, this coed sauna calls for nudity, so we strip down and nobody takes notice.

The next day, we awake to enjoy a huge breakfast at our hotel. If I didn’t have a train to catch, I would spend the morning at the restaurant and all day at the thermal spa. But the train calls, and by 8 a.m., we’re riding the rails again. It’s a long day on the train today — nine hours — but enjoyable. We arrive at the station only 15 minutes before our scheduled departure, another convenience of train travel.

We pass the time reading, napping, working (yes, there’s Wi-Fi), and enjoying the fantastic scenery. This part of our route travels by way of the UNESCO World Heritage Upper Middle Rhine Valley, taking us through charming villages, alongside hills topped with medieval castles, and past the Lorelei rock, famous in poems, songs, and folklore that tell the tale of the siren Lorelei, who called out to fishermen from the rock, distracting them with her beauty and causing them to crash their boats into the rocks below.

Arriving in Baden bei Wien (literally, Baden near Vienna), we transfer to our hotel, At the Park, which is both the name and the location, as it sits on the edge of Kurpark. The 200-year-old park is filled with colorful floral gardens, fountains, and monuments, including the Beethoven Temple. Atop the hill in the southeast corner of the park, this domed attraction overhung with ivy is not only a monument to the composer, but also the best place to watch the sunset.

Awaking refreshed, we’re ready to join our local guide for a walking tour. With 26,000 residents, Baden bei Wien is a bit larger than the towns we’ve explored thus far, and though the rainy October day keeps most inside, it isn’t difficult to imagine the wide pedestrian streets filled with spring and summertime crowds. After walking through the park, we head down below to explore the narrow tunnels leading to a glass dome looking down into the original spring that continues to flow after thousands of years.

We move on to the Beethoven Haus, a museum in the building where the composer spent some of his 15 summers in Baden. It was here, in a first-floor apartment with pastel-pink and green painted walls (amazingly rediscovered during restorations), that he composed the “Ode to Joy” section of his Ninth Symphony. We follow this with a visit to the Arnulf Rainer Museum. Dedicated to the works of the contemporary artist, the museum is housed in a stylish former bathhouse built in 1821. With paintings hanging above sunken marble tubs and in former changing cubicles, the building is just as impressive as the artwork and fits perfectly with the city’s heritage.

Late afternoon brings another train ride, this one a short three hours to the Hungarian capital of Budapest. By far the largest city we visit on this trip, Budapest has 123 thermal springs flowing beneath the city that fill a multitude of baths. We head straight to the famous Danube River for a dinner cruise with traditional Hungarian music and dancers. With the stunning scenery of the waterfront, no further entertainment is needed.

The evening continues with a look at Sparty, the spa party held every Friday and Saturday night at Széchenyi Thermal Bath. With DJs, lasers, and hundreds of partiers dancing and drinking in the enormous outdoor pools, the crowd is a bit young for us and so we move on to Rudas Bath. The five pools in the 450-year-old Turkish bath on the lower level are surrounded by arch-topped columns and domed ceilings, making people feel as if they’ve traveled back in time. The strong sulfur smell is testament to the mineral content of the waters. After soaking in each pool, we head up to the small, modern thermal pool on the top of the building. While the view overlooking the Danube and brightly lit buildings across is stunning, this particular Saturday night proves way too crowded with partiers and couples. After a long day, it’s time for bed.

Our final day brings us back to Széchenyi, where we dip in the multitude of indoor and outdoor pools, saunas, and steam rooms. Still, the things that set Széchenyi apart are its size — it’s big — and stunning architecture.

With our skin waterlogged, and about as relaxed as a person can get, we accept that it’s time to end our journey. Some of my travel companions fly home, while others take the train. I catch a taxi, arriving at my apartment within 15 minutes. Still, I’m a bit envious of the train travelers. It’s clear, I’m hooked on this greener, more leisurely, and very relaxing way of travel.