Ikebeji Temple Ruins

One Hundred Stone Towers on a Quiet Hillside

Climb the wooded slope above the small farming hamlet of Taira, in the western reaches of Kumamoto City, and you reach a terrace where one hundred low towers of piled stone stand in ten rows of ten. Each tower is a square of roughly 2.4 metres a side, rising only about 0.6 metres, built from rounded river stones the size of a human head. They sit at regular intervals of 2.4 metres, ninety-eight of them still in place. Nothing quite like this arrangement has been found at any other ancient temple site in Japan.

This is the site of Chihenji, a mountain temple whose name is written with characters that would more usually be read "Ikebe-dera." Local tradition has kept the older reading. The temple itself is long gone. What archaeologists uncovered here, on an east-facing slope at an elevation of about 130 to 140 metres, is the buried plan of a religious complex active in the 9th and 10th centuries, together with that strange field of stone towers behind it.

The hillside has a name of its own: Hyakuzuka, meaning "the hundred mounds." The name itself is a clue, and the excavations confirmed what it had been hinting at for centuries.

A Temple Born From a Dragon Legend

Before the spades arrived, Chihenji existed mainly in story. A picture scroll called the Chihenji Engi Emaki, now held by the Kumamoto Prefectural Museum of Art, tells how a monk named Mazumi, who had travelled from the old province of Yamato, built a temple beside a large pond called Ajifu-ike. An evil dragon was said to live in the water and bring harm to the people around it. Mazumi founded the temple to quell the creature.

The pond was real. Ajifu-ike appears in the Shoku Nihongi, an official chronicle compiled in 797, which places it firmly in the historical record. The pond was drained and filled during the era of the warlord Kato Kiyomasa around the turn of the 17th century, and houses now cover the ground where the water once lay.

A second source carries the temple's history forward. On the slope of nearby Nishihira-yama stands a stone stupa raised in 1337 and known as the Kaneko-to. Its carved inscription records that Chihenji was founded during the Wado era, between 708 and 715, that it burned down in 976, and that it was later rebuilt on a different site. The inscription names the original location "Hyakuto," the hundred pagodas. For a long time that name had no obvious referent. The hundred stone towers at Hyakuzuka answer the question directly, and they are the strongest evidence tying this hillside to the temple of the legends.

The full sequence of moves and rebuildings is still not entirely clear. The inscription and the excavated remains agree on the essential point: a Tendai-affiliated temple flourished here in the early Heian period.

What the Excavations Revealed

The first survey of the valley took place in 1958, when researchers began to suspect that a temple lay buried in the hills above Taira. Serious excavation started in 1986 and has continued, on and off, ever since. Two main features emerged from the ground.

The first is the central hall complex. It sits on a platform of roughly stacked, uncut stone, measuring about 22 metres north to south and 18 metres east to west. Four buildings stood on it. The central hall, three bays square and oriented north to south, occupied the highest level. Three further buildings enclosed it on the east, south and north, with roofed corridors linking the eastern building to those on the south and north. The platform was stepped: the north and south halls sat 0.35 metres below the centre, and the eastern building and corridor about a metre lower again. The top of the central platform was paved with fired clay tiles, except for a single bay at its core, and a strip of cut tuff stone, 0.7 metres wide and 11.4 metres long, ran along its western edge.

The second feature is the one that gives the site its character. Immediately west of the hall complex, a roughly square enclosure about 52 metres on a side was bounded by low stone walls on its south and west sides and by a wall around a metre high on the east. Inside it stand the hundred stone towers. They were not solid pagodas of cut stone but careful stackings of small rounded stones, and their sheer number, set out on a precise grid, has no parallel.

Pottery and roof tiles found in the soil dated the activity here. Everyday earthenware spans the early 9th century to the 10th. The roof tiles, including eaves tiles decorated with a nine-petalled lotus and others with a flowing arabesque, point to the early 9th century. From the stone towers came finials of tuff and sandstone, among them several sacred jewel shapes that once crowned them.

Why It Became a National Historic Site

Japan has many ruins of temples built into its mountains. Chihenji earned national protection because it does not look like the others. The Agency for Cultural Affairs designated the Hyakuzuka area a National Historic Site on 11 September 1997, covering 14,534.63 square metres, and added a further 3,542.97 square metres on 19 March 2002.

The reasoning rests on the stone towers. A combined layout of an enclosed pagoda field and a hall complex built from rough stone is, in the words of the official assessment, particular to Chihenji and without known parallel anywhere in the country. The towers consume an enormous quantity of stone and are laid out on a deliberate, almost ceremonial grid. Among the ancient temples founded in mountain settings, this one stands apart for the originality of what its builders chose to make.

What the hundred towers meant to the people who built them is not fully understood. They may have been votive structures, each an act of devotion, raised one by one until the grid was complete. The site invites that kind of question rather than answering it.

Visiting the Site Today

Restoration work on the Hyakuzuka area ran from 2012 to 2015 and was completed in the spring of 2016. The approach taken by the city was conservative. At the hall complex, the foundation stones and the stone platform were restored and put on display roughly as the excavators had found them. Over the pagoda field, a layer of earth-toned paving was added to protect the buried remains from erosion, and the genuine excavated stone stackings are shown in place rather than reconstructed from new material.

Explanatory panels, a route map and a model of the reconstructed buildings have been installed, and a replica of the Kaneko-to stupa lets visitors read the inscription without climbing Nishihira-yama. The walk among the towers takes only a short time, but it rewards an unhurried pace. The grid is best understood from the slope above, where the full pattern of ten by ten becomes visible at once.

A point worth knowing before you arrive: the site is open ground on a hillside, not a staffed museum. There is no admission fee and no fixed opening hours, though daylight and dry weather make for a far better visit on the unpaved upper paths.

Getting There and What Lies Nearby

Chihenji sits in the hills behind Kumamoto Station, close enough to reach on a half-day outing. By car the site is about 15 minutes from the station, with parking for around five vehicles; the final stretch of road is narrow, and vehicles larger than a microbus may struggle. Without a car, the simplest option is a bus from Sakuramachi Bus Terminal: the Sanko Bus services U-2 and U-3 stop at Ikenoue, about 35 minutes' walk from the site. Energetic walkers can also reach it on foot from Kumamoto Station in roughly 70 minutes, a route that doubles as a pleasant climb through the foothills.

Local volunteer guides offer free tours of about an hour, covering both the archaeology and the dragon legend. They need to be booked at least a week ahead through the city's Cultural Properties Division.

The surrounding area carries the same story in lighter form. The Ajifu-ike viewpoint looks out over the residential land that now fills the legendary pond. At Ikegami Elementary School, two large dragons climb the outer wall, a modern nod to the creature Mazumi is said to have subdued. The whole district lies on the skirts of Mount Kinpo, a 665-metre peak that has shaped settlement here since well before the temple was built, and the climb to Hyakuzuka offers wide views back over the valley.