Akeai Tomb

Akeai Kofun: A Square Tomb on the Anō River Plateau

Akeai Kofun measures roughly 60 meters along each side and rises about 10 meters above a low plateau in the Anō district of Tsu City, Mie Prefecture. It was built in the early fifth century, during the middle phase of the Kofun period, the long age when Japan's emerging chieftains raised great earthen tombs across the archipelago. The Kofun period takes its name from these very mounds.

What makes this tomb stand out is its outline. Most large mounds of the era followed a keyhole plan, with a round rear joined to a flaring trapezoidal front. Akeai Kofun is instead a square mound, and a rectangular platform extends from both its northern and southern faces. That symmetry gives it a profile found at very few sites anywhere in the country.

The mound went unrecorded for centuries. In 1949 a group of students from the geography and history club of a Tsu high school examined an overgrown rise on the plateau and recognized it as an ancient burial mound. Three years later the government listed it as a National Historic Site.

A Chieftain Buried Above the Anō River

The tomb sits on a tongue of land about 40 meters above sea level, extending eastward from Mount Kyōgamine along the right bank of the Anō River. Anyone standing on the summit looks out over the valley floor where rice has been grown for well over a thousand years.

After the 1949 discovery, the site drew attention from established archaeologists, including Umehara Sueji and Saitō Tadashi, two figures central to the study of Japanese antiquity in the mid-twentieth century. Their surveys confirmed the scale and form of the mound and led to its designation on 11 October 1952.

No excavation has ever reached the burial chamber. The person interred here, the grave goods placed alongside them, and the exact construction date all remain unknown. What the surface evidence does show is clear enough: in the early fifth century this was the largest tomb in the entire Anō River basin. No later mound of comparable size or form was raised anywhere in what is now Mie Prefecture, which makes Akeai Kofun a fixed point for anyone tracing the rise and decline of local power in the region.

An Unusual Form Among Japanese Tombs

Square mounds, known in Japanese as hōfun, are far less common than the keyhole tombs that dominate the period. Akeai Kofun is among the largest of its kind, ranked roughly tenth nationally for a square mound. Including the two projecting platforms, the structure stretches 81 meters from end to end.

Those projections gave the tomb an older nickname, sōhō-chū-hōfun, loosely "a square center with a square at each of two ends." Early researchers wondered whether the central mass and its extensions formed a single integrated shape, almost a variant of the keyhole type. The reading accepted today is simpler: a square mound to which two ritual platforms, called tsukuridashi, were attached at front and back. Platforms of this kind were stages for funerary ceremony rather than parts of the grave itself.

The designation in 1952 rested on two points. The mound is a remarkably complete square form, and the pairing of square platforms on opposite sides is exceptional. Together these qualities make the tomb a rare physical record of how a regional ruler chose to be commemorated.

Walking the Mound

The main mound was raised in two tiers. The lower tier measures about 60 meters along its base and 48 meters across the top, standing roughly 2 meters high. The upper tier rises another 6 to 7 meters, bringing the total to about 10. Climbing it today is a short walk up a grassed slope, but the change in height is enough to lift you above the surrounding fields.

The two platforms differ slightly in scale. The northern one runs about 10 meters long and 17 meters wide; the southern one is larger, near 13 by 21 meters. Standing on either, it is easy to picture them crowded with mourners and offerings.

When the tomb was new it looked nothing like the green hill of today. Its slopes were faced with fukiishi, a covering of fist-sized stones, and rows of cylindrical clay tubes called haniwa ringed the terraces. Among the fragments recovered from the surface are figurative haniwa shaped as houses, shields, and ceremonial parasols, along with a stand for sue ware, the hard gray stoneware then newly arrived from the Korean peninsula. A shallow moat once encircled the base, and traces of it can still be read in the ground.

Akeai Kofun did not stand alone. Five smaller square mounds are scattered around it, understood as satellite tombs for people connected to the central figure. The best preserved, a 22-meter mound locally called Kozuka, or "little mound," still keeps its stone facing and haniwa rows. A sixth satellite once stood nearby but was lost to farmland clearance in the 1950s.

Visiting the History Park

The tomb and its satellites now lie within Akeai Kofun History Park, an open green space with no admission gate and no fixed hours. Visitors are free to walk up onto the main mound and across the platforms, which is rare access for a tomb of this rank. The grounds are planted with cherry trees, and in early April the mound becomes a quiet local spot for blossom viewing.

There is no visitor center on site, so it helps to know the basics before arriving. Excavated haniwa and pottery from the tomb group have been displayed in the Anō district's local history collection; checking its current location with the Tsu City tourism office before a visit is worthwhile, as the collection has moved in recent years. Sturdy shoes are sensible, since the slopes can be slippery after rain.

Around the Site

The Anō district rewards a slower visit. Anō Central Park, a short distance away, offers wide lawns and walking paths for a break after the tomb. Tsu City itself, the prefectural capital, holds two of the area's major religious sites: Senjū-ji, head temple of the Takada branch of Jōdo Shinshū Buddhism, whose main halls are themselves National Treasures, and Tsu Kannon, counted among the country's notable Kannon temples. Combining Akeai Kofun with one of these gives a single day that runs from the fifth century to the present.