Shizuhayama Tomb

Shizuhatayama Kofun: Inside Shizuoka's Largest Ancient Stone Chamber

Behind the main hall of Otoshimioya Shrine, one of the shrines that make up the Shizuoka Sengen Shrine complex, a flight of roughly one hundred stone steps climbs the southern end of a ridge called Shizuhatayama. At the top, about 50 meters above the Shizuoka plain, sits a rounded earthen mound roughly 32 meters across and 7 meters high. This is Shizuhatayama Kofun, the burial place of a powerful local figure who lived in the latter half of the 6th century. Inside it lies a stone chamber large enough to walk into, holding a coffin carved in the shape of a house. It is the largest tomb chamber of its kind in Shizuoka Prefecture.

The mound is the third and grandest of a cluster of tombs strung along the ridge, raised over roughly two centuries by the leading families of the area. Visitors reach it through shrine grounds that have drawn worshippers since long before written records can confirm, which makes the climb feel less like a detour to an archaeological site and more like a walk into the deep past of the city.

A Tomb Found, Lost, and Found Again

This tomb was known long before modern archaeology arrived. Edo-period documents describe how it first came to notice. According to the Suruga Kokushi of 1783 and the Suruga-ki of 1818, sometime during the Meiwa era (1764 to 1772) a large tree on the summit was toppled by a strong wind. The roots tore open a hole, and a person who climbed down through it found a room built of stacked stone with a stone chest resting inside. The opening was later sealed, and the chamber slipped out of common memory for the better part of two centuries.

It returned to attention in 1949, when the archaeologists Goto Moriichi and Saito Tadashi carried out the first scientific excavation. Their survey fixed the shape of the mound and revealed the full scale of what lay within: a horizontal-entry stone chamber built of massive boulders, with a large house-shaped coffin set near its mouth. The findings were judged important enough that the site was named a National Historic Site in 1953.

The Stone Chamber and Its Coffin

The chamber is what archaeologists call a yokoana-shiki sekishitsu, a corridor-style chamber entered from the side rather than from above. It has three parts: the genshitsu, the main burial room at the back; the sendo, a roofed passage leading to it; and the zentei, an open forecourt beyond the passage. From the rear wall of the burial room to the ring of stones around the foot of the mound, the structure runs 18.2 meters.

Its plan has an unusual silhouette. The passage is noticeably narrower than the burial room, giving the whole layout the outline of a battledore paddle. The burial room also rises to roughly twice the height of the passage. Both features echo the large stone chambers built in the same period in the Kinki region, the political heartland of early Japan, and they suggest that whoever was buried here had connections reaching well beyond the Shizuoka plain.

Near the entrance to the burial room stands the coffin. It was cut from a single block of tuff quarried on the Izu Peninsula, hollowed into a box and capped with a lid shaped like a pitched roof, which is why this type is called an iegata sekkan, a house-shaped coffin. It measures 2.9 meters from end to end. Square knobs project from the lid, three pairs along the sides and one pair at each end, used to bind and lift the heavy stone. Where the lid meets the body, traces of red ochre still mark the seam.

What the Grave Goods Reveal

By the time of the 1949 excavation, the coffin had already been robbed. Looters had broken a hole in its side, and only fragments of a gilt-bronze crown cap and a few glass beads remained inside. The ground around the coffin held a far richer record. From it came pottery in both Sue and Haji wares, lamellar armor, long swords and iron arrowheads, gold rings, iron tools, and a bronze mirror ringed with small bells. Among the most telling finds were gilt-bronze horse trappings, including ornamental fittings hung with tiny dangling plaques.

Objects of this quality were not local work. The gilt-bronze ornaments and horse gear closely resemble those from elite tombs in the Kinki region, including the renowned Fujinoki Kofun in Nara. That resemblance is why the person buried here is understood to have been more than a regional strongman, someone tied to the Yamato court that was consolidating power across the islands. The artifacts span a range from the late 6th into the early 7th century, which suggests the chamber was opened for burial on more than one occasion.

What to Look For on a Visit

The stone chamber cannot currently be entered. Rainwater has been seeping in and damaging the stonework, so a protective sheet now covers the mound and the interior is closed to general visitors. Even so, the chamber is lit during daytime hours, and you can look through the gateway from outside to see the coffin and the stacked boulders of the walls.

Pause at the gate itself. Its design carries a phoenix motif drawn from the silver-inlaid pattern on a sword pommel found in the tomb, a quiet modern echo of the craftsmanship of the buried objects. In front of the mound, an outdoor model and an illustrated panel set out the chamber's structure and show photographs from the excavation, including the layered cross-section of the mound that the restoration team rebuilt with care.

The mound visitors see today is itself a reconstruction. Between 1993 and 1996 the city carried out preservation work that returned the tomb to something close to its original built form, after centuries of natural collapse and human disturbance had blurred its outlines.

Getting There and Nearby

Shizuhatayama Kofun sits within the grounds of Shizuoka Sengen Shrine, a short bus ride north of JR Shizuoka Station. Buses from the station stop near the shrine's large red torii gate, and from there the route into the precincts and up the stone steps is straightforward. There is no dedicated parking for the tomb. Admission is free, and the chamber is lit from 8 a.m. to 6 p.m.

The shrine complex itself rewards an unhurried visit. Its lavishly decorated halls, built and rebuilt across the Edo period, are worth time before or after the climb. The wider ridge has been laid out as Shizuhatayama Park, with walking paths that pass the other mounds of the same tomb cluster. The objects recovered in the 1949 excavation were long shown at a municipal cultural-properties museum in the city; that museum closed at the end of 2021, so anyone hoping to see the original artifacts should check current arrangements with the city before visiting.