The Japanese Romantic Road

1 hour 40 minutes on National Route 18 from Takasaki

This otherworldly environment of craggy black rocks was created in 1783 when Mt. Asama violently erupted, sending out a stream of lava that was 7 kilometers wide and 8 kilometers long. Accounts say the eruption blacked out the sky for days. The destructive flow devastated the village below, where the stone park now lies. The park’s Japanese name, Onioshidashi Park, means “demon pushing out rocks.” Over the years, the area has been populated by various moss and alpine plant species.

Choose from the 30-, 40-, or 60-minute hiking courses that meander through the sights. For a shorter visit, walk the loop to the Asamayama Kannondo Temple, built in 1958 to remember those who died in the disaster.

You can see Mt. Asama, still an active volcano, visibly smoking in the background. Joshin’etsukogen National Park spreads out in the opposite direction.

40 minutes on Regional Route 59 and National Route 292

The next stop is one of Japan’s most renowned onsen towns. Schedule at least a night or two to fully appreciate the sights of Kusatsu Onsen, and to take in its relaxed pace of life.

The picturesque town is centered around Yubatake, a hot water field that emits a strong, sulfurous smell. The very hot, mineral-rich onsen water is piped to nearby bathhouses, where you can take part in the area’s traditional bathing techniques. Local legends claim these steaming, strongly acidic waters can cure anything but lovesickness. There are six spring sources in Kusatsu, each with varied mineral content. The best way to find your favorite is to visit as many bathhouses as you can: each one has its own charm.

Another must-see local tradition is “yumomi,” a water-stirring performance held at Netsunoyu, several times a day. The performance mimics the water-cooling method used since the Edo period (1603–1868), stirring the water with wooden paddles. Traditional songs and dances accompany the show. This spectacle is unmissable when you’re in Kusatsu and is depicted throughout the town on souvenirs and even manhole covers.

Evenings are relatively lively in Kusatsu. Visit Netsunoyu to see a traditional rakugo performance in which a performer sits and uses minimal props to tell a comedic story. Soak in the illuminated outdoor footbaths of Sainokawara Park or visit a cozy izakaya pub in the center of town.

1 hour on Regional Route 55 and National Route 353

Shima Onsen is best known for a ryokan inn rumored to have been an inspiration for the hit Studio Ghibli animated film “Spirited Away.”

This quiet town is a good place to unplug and enjoy the surrounding nature. In the warmer months, visit Lake Okushima or Lake Shima to appreciate their strikingly blue waters, known locally as “Shima Blue.” Get active on the water through a canoe or stand-up paddleboarding tour.

Relax in the evening by bathing in one of Shima’s soothing onsen. The water is rich in sodium chloride, calcium chloride, and sulfate ions, which purportedly have anti-aging properties and help to soothe skin conditions. Evenings are quiet in Shima, giving you the opportunity to enjoy the tranquility and hospitality of your ryokan.

40 minutes on National Routes 353 and 145 from Shima

One of the most romantic—and surprising—spots along the route is an authentic Scottish castle. Lockheart Castle was built near Edinburgh in 1829, before being dismantled and moved to Gunma, where it was reconstructed in 1993. It is now a popular wedding venue, with its own chapel and plenty of photogenic spots around the grounds. The themes of royalty and Britain run throughout. Among the diverse exhibitions, you’ll find fun costume jewelry and other possessions that belonged to British royalty and Hollywood legends, including Audrey Hepburn and Marilyn Monroe. Try out the castle’s Princess Experience, in which visitors can choose from more than 150 dresses as well as men’s tuxedos to wear for commemorative photos.

40 minutes on National Route 120

Stop in Oigami Onsen to visit the mountainside village’s public onsen. Some of the facility’s outdoor baths (rotenburo) overlook Katashina Gorge and the fast-flowing river below. The warm water is the perfect temperature for lingering—particularly in the tub with bubbles, which add to the indulgence.

10 minutes on National Route 120

A short drive along the Katashina Gorge, Fukiware no Taki Falls adds a dramatic flourish to the end of the Gunma stretch of the Japanese Romantic Road. Walk along the undulating bedrock to see these 7-meter-high, 30-meter-wide falls up close. A short path leads you further along the gorge, where you can admire the smooth, unusually shaped rocks that have been carved out by millennia of cascading water.