The 'caves' were originally misidentified as dwellings by the public until archaeological investigations in the late 19th century revealed them to be tombs.
The rare glowing moss (Schistostega pennata) found in the caves is protected as a natural monument.
There are exactly 219 individual tomb openings recorded at the site.
The caves were carved into a soft sandstone cliff, a technique indicative of regional Kofun-era burial practices.
During World War II, a portion of the hillside was repurposed as an underground munitions factory for the Nakajima Aircraft Company.
Yoshimi Hyakuana is an archaeological site in Saitama Prefecture featuring over 200 man-made caves carved into a sandstone hillside during the late Kofun period (6th to 7th centuries). Originally thought to be dwellings for ancient people, excavations confirmed these structures are necropolis tombs for influential local families. The site includes two museums, the Yoshimi Hyakuana Museum and a secondary facility, which house artifacts recovered from the burials and explain the construction methods. Visitors can walk along designated paths to view the cave openings, some of which are accessible for close-range inspection. The area is also known for a population of glowing moss (hikari-goke) that grows inside the darkened chambers. The site is recognized as a National Historic Site of Japan. The surrounding park maintains a hillside topography providing a view of the Hiki District.
From the base of the hill looking up at the honeycomb-like pattern of the tiered tomb openings.
Bring a small flashlight to better observe the interior of the tombs and the glowing moss.
Wear comfortable, sturdy walking shoes as the site is located on a sloped, uneven hillside.
Check the local visitor center for guided tour availability if you want deeper historical context.
Do not attempt to climb or scramble off the marked paths; the sandstone terrain is prone to erosion and instability.
Do not enter prohibited cave chambers or touch the walls, as the sandstone is fragile and the moss is protected.
