Tatsuyama Stone Quarries
Tatsuyama stone was formed about 9,000 years ago. It is hyaloclastite, an aggregate of fine, glassy debris formed by the sudden contact of magma and cold water, a rare material that has long been desirable for construction purposes due to its relative softness. The stone is thought to have been extracted at the Tatsuyama quarries since the Kofun period (ca. 250–552). The location of the quarries (near the mouth of the Kakogawa River, which flows into the Seto Inland Sea) is ideal for transporting the excavated stone.
Tatsuyama stone was first used for stone coffins. Between 740 and 744, it was chosen as the foundation stone for the palace of the emperor at Kuni, then the capital of Japan in present-day Kyoto Prefecture.
In the medieval and early modern periods (1185–1867), the stone was used for structures such as pagodas, monuments, and Buddhist statues. In modern times, it has been used as the foundation stone for wooden buildings and as a material for grave markers, signposts, and torii gates at Shinto shrines. The most famous extraction from the Tatsuyama quarries is the Ishi no Hoden (Stone Treasure Hall), a megalith at Takasago’s Oushiko Jinja Shrine believed to have mystical power.
Quarrying methods have been adapted over the centuries, reflecting the changing use of the stone. This has made the quarries an important site for understanding of the evolution of Japan’s quarrying technology. Today, two Tatsuyama quarries remain in operation.