Sanryoo Shrine Tamagaki

Sanrureo Shrine Tamagaki: A Sacred Stone Fence Guarding an Ancient Legend

Nestled on a gentle hilltop in the Iiyama district of Marugame City, Kagawa Prefecture, the Sanrureo Shrine Tamagaki (讃留霊王神社玉垣) is a remarkable cultural artifact that stands at the intersection of ancient mythology, Shinto worship, and Edo-period craftsmanship. Registered as a national tangible cultural property in 2018, this granite stone fence encircles what is believed to be the burial mound of the legendary Sanrureo King — a heroic figure deeply woven into the founding mythology of Sanuki Province (present-day Kagawa Prefecture).

Unlike many cultural properties that can be appreciated through architecture or artistry alone, the Sanrureo Shrine Tamagaki derives its profound significance from the unique way it physically connects the worlds of the living and the sacred dead. The fence defines the boundary of the divine, marking the top of the ancient burial mound that serves as the shrine's object of worship — its goshintai, or sacred body.

The Legend of Sanrureo King: Slayer of the Great Evil Fish

To understand the tamagaki, one must first understand the legend it protects. According to ancient Sanuki tradition, during the reign of Emperor Keiko (approximately the 1st–2nd century), a monstrous evil fish terrorized the Seto Inland Sea, attacking ships and tormenting fishermen. The emperor dispatched a brave prince — identified in various sources as Takekaikoo (武殻王), a son of the legendary hero Yamato Takeru, or alternatively as Prince Kamikushi — to subjugate the creature.

The prince succeeded in the daring mission. One of his soldiers was swallowed by the beast, but drawing his sword within its belly, the warrior slew the creature from within. Having liberated the seas of Sanuki, the prince was granted dominion over the province and remained there for the rest of his life. The people honored him with the title "Sanrureo" (讃留霊王), meaning "the spirit king who remained in Sanuki." His descendants are said to have become the Aya clan, an influential family in the region's history.

The burial mound at this shrine is traditionally regarded as the final resting place of this legendary king, making it one of the most historically resonant sites in Kagawa Prefecture.

The Tamagaki: Structure and Significance

The tamagaki itself is a stone fence constructed of locally quarried granite during the late Edo period (approximately 1830–1868), with additional sections added during the late Meiji era. It has a total length of approximately 20 meters and forms a rectangular enclosure around the summit of the circular burial mound (enbun) that constitutes the shrine's goshintai.

The east-facing side of the tamagaki is left open, creating a passage-like connection between the sacred mound and the heiden (offering hall) of the shrine. This configuration is highly distinctive — rather than enclosing the object of worship entirely, the fence simultaneously demarcates the sacred space and provides a ritualistic pathway linking the world of the worshipper with the divine resting place of the Sanrureo King.

The tamagaki was registered as a national tangible cultural property on March 27, 2018, under registration number 37-429. The registration criteria note that it "contributes to the historical landscape of the nation," recognizing how this stone fence symbolizes the unique composition of the shrine and shapes the cultural character of the surrounding area.

Why Was the Tamagaki Designated as a Cultural Property?

The Sanrureo Shrine Tamagaki was registered as a tangible cultural property for several interrelated reasons. First, it exemplifies a rare and distinctive shrine configuration in which an ancient burial mound serves directly as the object of worship, with the tamagaki defining the sacred precinct atop the tomb. This arrangement is uncommon even within Japan's rich tradition of shrine architecture.

Second, the tamagaki serves as a physical embodiment of the region's deep historical identity. The Sanrureo King legend is central to the cultural memory of Sanuki Province, and the stone fence — constructed with care from local granite — represents the community's enduring commitment to honoring this heritage across generations.

Third, together with the shrine's heiden (which was also registered as a tangible cultural property on the same date), the tamagaki contributes significantly to the historical landscape of the Marugame area, preserving a traditional sacred precinct within the agricultural plains of southern Marugame.

Highlights and Things to See

Visitors to the Sanrureo Shrine will find a compact but deeply atmospheric site that rewards careful attention. The tamagaki crowning the burial mound is best appreciated by walking the grounds slowly, observing how the granite posts and rails create a defined sacred rectangle atop the ancient tomb. The open eastern side, aligned with the heiden, invites you to contemplate the spiritual connection between the worshipper and the legendary king.

The heiden itself, also a registered tangible cultural property, is a one-bay structure with a hip-and-gable cypress-bark roof, supported by round pillars with elaborate bracket complexes. Notably, it features lattice doors on both the front and the rear — the rear doors face the burial mound, allowing the building to serve as a spiritual conduit between worshippers and the goshintai.

The burial mound behind the shrine is believed to be a keyhole-shaped kofun (front-square, rear-round tumulus) dating to the early Kofun period (3rd–4th century). The mound is aligned directly north, with the shrine's approach road (sando) extending toward Mount Iino (Sanuki Fuji), the iconic conical peak that serves as a landmark of the Marugame area. On clear days, the view from the shrine grounds toward this "Sanuki Fuji" is spectacular.

The Shrine Within the Yasaka Shrine Complex

The Sanrureo Shrine is part of the broader Yasaka Shrine (八坂神社) complex in the Shimohōgunji area of Iiyama. This Yasaka Shrine — distinct from the famous Yasaka Shrine in Kyoto — serves as the local guardian shrine (ujigami) for the community. The Sanrureo Shrine and its tamagaki occupy a position of special reverence within this complex, as they preserve the region's most ancient legendary traditions.

The shrine grounds are quiet and peaceful, set on a small rise above the surrounding rice paddies. The atmosphere is one of deep rural tranquility — a stark and refreshing contrast to Japan's more heavily visited shrine sites.

Surrounding Area and Nearby Attractions

The Sanrureo Shrine is located in the agricultural heartland south of central Marugame, offering visitors a chance to explore both cultural heritage and natural beauty in the Sanuki region.