It's probably a nightmare for people afraid of dark, tight spaces -- especially since those spaces were once filled with the dead.
But if you're feeling a little daring or aren't easily spooked, a trip to the Yoshimi Hyakuana tombs in Japan may be just the kind of morbid, yet educational, experience you're looking for.
Hyakuana literally translates to a hundred caves in Japanese, but you'll actually find 219 caves to explore in Yoshimi, located in the Saitama Prefecture -- about an hour north of Tokyo.
What initially sparked my interest in the Hyuakuana tombs was learning the tombs' history as both an ancient Japanese burial ground and a World War II underground munitions factory.
The caves were originally built sometime in the late 6th to early 7th centuries and served as tombs large enough for at least two bodies, according to Yoshimi's town website.
In 1923, the caves were named a national historic site. Construction began in an area around the caves from 1944 to 1945 -- resulting in deeper caves being built, according to the website. As World War II wound down in the Pacific, the Japanese plan was to move a factory in Tokyo underground. However, the underground site in Tokyo was bombed heavily at the end of 1944, and munitions production dropped steeply. This eventually led the Japanese to move their factory in Saitama underground to the area around Yoshimi Hyakuana, according to the website.
During my visit I was able to go inside countless numbers of the little tomb caves. I didn't find any skulls or bones lying around like some clip out of an Indiana Jones film. What I did find was an empty and terribly uncomfortable, tight space.
Looking inside, I also found many of the cave walls lined with a rare luminescent green moss known as Hikarigoke, which only added to the eerie atmosphere of the tombs.
The munitions caves, by contrast, offer far more space than the former tombs. Walking in the munitions caves you don't really see the remains of any equipment they might have used back then, which is a shame. But the spaces do give you a sense of the dire state Japan must have been in to move a munitions factory deep into caves.
The area is well-lit and the caves go quite deep into the cliff. Overall, the area seemed quite safe and the visitors were mostly Japanese families.
It is quite fascinating to consider that in one area of the Hyakuana cliffs the dead were laid to rest, while in another, munitions meant to bring death to Japan's enemies were being built. Keeping all that history in mind really makes a visit to the Yoshimi Hyakuana tombs a very interesting one.
KNOW & GO
Hours: Open all year, 8 a.m to 5 p.m. Closed Sundays.
Admission: General admission 300 yen; elementary school students 200 yen; and free for any child less than the elementary school student age.
Directions: Take the Tobu Tojo line from Ikebukuro Station. Get off at Higashi Matsuyama Station and take the east gate exit. From there you can take an 20-minute walk from the station to the caves or take a 5-minute bus ride. If you're walking, head towards the nearby Family Mart and turn right. From there, walk straight along the road. Eventually you should see the caves as you approach on the left side.