Crawling in and out of graves isn’t everyone’s idea of a good time. For those willing to give it a try, though, Yoshimi Hyakuana in Saitama Prefecture makes for an interesting day trip out of Tokyo.

Literally meaning, “100 holes of Yoshimi,” the Yoshimi Hyakuana National Historic Site preserves 219 ancient tombs carved into a soft sandstone hillside between the sixth and seventh centuries.

After the holes were rediscovered in the 1880s, the first Japanese archaeologist to work there believed they had been cave dwellings. However, further research in the 1920s showed they were burial sites.

The graves are similar to more common tunnel tombs found throughout Japan. However, the Yoshimi site is special because so many have been dug together in a single hillside. Unfortunately, most of the records and objects from the original excavations have been lost, so many questions about the site will never be answered. Experts nonetheless believe that the tombs were dug for the internment of powerful leaders of regional clans and for Chinese and Koreans who settled in Japan to introduce continental Asian culture.

Staircases now lead to walking paths up and around the hill. The 10-minute climb to the top allows visitors to get a close-up view and access to several of the tombs. Despite differences in size, most share a basic common form, with a small hole providing entry to a square room with a 10- to 20-cm-high platform for the body carved out of the wall. Some tombs, with two platforms, were dug for the interment of multiple bodies.

In 1945, the Japanese government tried putting the area to another use. Between 3,000 and 3,500 conscripted Korean laborers were made to dig a series of large tunnels into the hillside for an underground Nakajima aircraft-engine factory safe from American bombers. However, the war ended before the factory entered production.

Nowadays, visitors can explore about 10 percent of those wartime tunnels. Gates block off the rest of the extensive tunnel system that extends far into the surrounding hills and includes wells and even toilets.

Meanwhile, the park’s admission fee also includes access to two museums. One small one has Japanese explanations of the area’s history and a diorama of Matsuyama Castle, which formerly stood atop a nearby hill. The newer and larger Yoshimi Town Archaeological Center displays artifacts recovered from the tombs, as well as tools, pottery and other items from the Jomon and Kofun eras spanning 2,500 B.C. to A.D. 600.

In addition, for a small fee, visitors can make haniwa clay statues like those used in burial rituals in the Kofun Period (third to sixth century A.D.), or necklaces and cell-phone straps using replicas of the magatama comma-shaped stone pendants that were widespread throughout the country until the end of the Kofun Period.

However, if natural history interests you more than ancient history, a few of the caves are home to a luminescent moss called hirakiri goke that is a designated Natural Monument. The moss appears to glow because its cells reflect light, which helps it to grow in low-light areas where other vegetation struggles to survive.

Benches inside the park and grassy stretches next to the nearby river make the area a nice picnic spot. If you don’t take your own lunch, several small shops open year-round just inside and outside the park gate sell noodles and snacks as well as souvenirs. Travelers eager to try local specialties should buy gokabo sweets. These Saitama specialties are rolls made from glutinous rice and sugar syrup, then dusted with soybean flour. The Takahashi shop in front of the Yoshimi Hyakuana still makes its gokabo by hand.

O verall, unless you have the misfortune to visit the same day as a school tour, the whole area is usually pleasantly uncrowded — except, that is, in spring, when the cherry trees lining the nearby Ichino River attract lots of visitors.

Also, located just across the road from the tombs are more sights worth checking out. One is the Iwamuro Kannon Hall, which you pass on your way to and from the bus stop. The temple is built on stilts over a cave containing 88 stone images of Kannon, the Bodhisattva of Compassion.

From behind the temple it’s a short hike up a steep trail to the top of the hill where Matsuyama Castle once stood. Constructed between 1394 and 1428, the castle became the scene of several fierce battles during the Warring States period, which spanned some 150 years prior to the unification of Japan in 1603. Control of the castle passed back and forth between the competing Uesugi and Hojo clans after a siege in 1537 and two in 1563. Then, in 1601, the Hojo clan abandoned the castle when it no longer needed it as a strong point. Today, though the only visible remnant of the fortification is the dry moat, it is nice to walk around the flat hilltop, whose paths sometimes get overgrown with weeds in summer.

Next to Iwamuro Kannon are the remains of what locals call the Gan Kutsu Hotel, now protected behind a chain-link fence. A farmer named Minekichi Takahashi carved an entranceway, staircases, and several rooms complete with balconies into the cliff side. Takahashi began work in 1904 and, using only a chisel, continued digging and carving until his death in 1925.

Despite the name given to the ruins, Takahashi’s efforts were only a hobby; he never actually intended to open a hotel. The name Gan Kutsu Hotel is a play on the Japanese for “rock face” (gan); “cave” (kutsu); and “is digging” (hotte iru). Today, from behind the rusting fence, the gated-up entrance and windows don’t look like much, but pictures showing the “hotel” in its glory days, complete with brick facade, can be seen in the Hyakuana gift shop run by Takahashi’s family.

Those with more energy and time to spare can enjoy walking to some of Yoshimi’s other attractions. A pleasant 40-minute stroll from Hyakuana Park leads past farmers’ fields and houses, then a statue of the Kitamuki Jizo and a shrine before eventually bringing you to Yoshimi Kannon, also known as Anraku-ji Temple. The way is well signposted, though visitors should take note of the kanji used for the various place names along the route by consulting the map board to the left of the Hyakuana entrance.

The temple was founded 1,200 years ago, though the main hall and pagoda were rebuilt after being razed during 16th-century battles. After touring the temple grounds, head down the small stone staircase to the right of the large Buddha statue and then left for about 10 minutes to reach Haccho-ko Pond, which it takes about 20 minutes to walk around. At the far end of the pond is a hillside containing more than 500 tombs, many still unexcavated. Known as the Kuroiwa Oketsu tombs, they are believed to date from around the same period as those at Yoshimi Hyakuana. From there, simply retrace the 2.5-km route back to Yoshimi Hyakuana, and head off where you will.

Getting there: From Higashi Matsuyama Station on the Tobu Tojo Line, take the East Exit and board a bus from Stand 3 bound for Kounosu Menkyo Center — there are usually two an hour during the day. Get off after about five minutes at the Hyakuana Iriguchi stop and continue walking for about five minutes in the direction the bus was traveling, crossing a bridge over the river before reaching a sign in Japanese indicating the left turn to the park entrance. Alternatively, take a bus from Kounosu Station on the JR Takasaki Line. Leave by the East Exit and take a bus bound for Higashi Matsuyama Eki. The trip takes about 25 minutes. Entry to Yoshimi Hyakuana is ¥300 for adults and ¥200 for children. It’s open every day, year-round, from 8:30 a.m till5 p.m.

In line with COVID-19 guidelines, the government is strongly requesting that residents and visitors exercise caution if they choose to visit bars, restaurants, music venues and other public spaces.