Kanpakuzawa, Hayakawa Group:
From the Izu peninsula, bound for Edo: building stone used in the walls Edo castle. Various markings are engraved on the stones.

A view of the excavation at the Hayakawa stone quarry

Engraved marking on a piece of split stone A circle 11 cm in diameter with a cross inside it was engraved with a chisel on this stone.

Stones cut for use in castle walls Along a straight line on a piece of stone to be cut for use in a castle wall, slots in the shape of inverted trapezoids or the letter U are gouged with a chisel, and the stone is then split away as planned by driving wedges into the slots.

Characters engraved on a natural stone surface The characters can be read as (to the left).

Photos courtesy of Kanagawa prefectural board of education.

A view of the quarry site
Workmen drive wedges into the stone (at center), and haul it away with a sled (upper right). (Artist’s reconstruction by Hayakawa Kazuko)

Distribution of quarry sites on the Izu peninsula

Adapted from Kaneko Hiroyuki and Sugiyama Hirō, “Edojō no ishikiri chōba” [Stone quarries of Edo castle], in Ishigaki fushin no fūkei o yomu [Interpreting scenes of castle wall construction] (Department of Historic Heritage, Tohoku University of Art and Design, ed., 2003); Hakkutsu sareta Nihon rettō 2007 [Excavations in the Japanese Archipelago, 2007] (Bunkachō [Agency for Cultural Affairs], ed., Asahi Shimbunsha, 2007).

Kanpakuzawa Branch, Hayakawa Stone Quarry Group, Odawara City, Kanagawa Prefecture

The Kanpakuzawa branch of the Hayakawa stone quarry group is located at the western edge of the city of Odawara in southwestern Kanagawa prefecture, at its border with the town of Hakone.

Topographically the branch is on the eastern base of the Hakone caldera, where it spreads over a broad area on a northward-facing slope, around 200 m in elevation, that was carved out by the Kanpakuzawa, a tributary stream of the Hayakawa river flowing from the center of Mt. Hakone out to Sagami bay.

Supplying building stone at the time of construction of Edo castle

This site is where stone for the castle walls were quarried on the occasion of the construction of Edo castle, conducted by mobilizing numerous daimyo at the start of the Edo period (the first half of the seventeenth century).

The region from the Hakone caldera across the Izu peninsula was known at the time as a source of andesite, a hard volcanic rock, and numerous quarries were operated mainly along the coast of the region by the tozama daimyo (former opponents of the Tokugawa forces) of western Japan, who were ordered by the Edo bakufu to construct the castle walls.

Markings are discovered – of the stone masons and daimyo who undertook the construction?

In the excavation conducted in fiscal 2005, quarry sites, work sites for shaping the cut stone and staging areas where the worked stone was gathered, plus a road-like feature for hauling the stones, were among the finds verifying the variety of tasks that had been conducted here.

Stones cut from the quarries for use in the castle walls were uniformly trimmed into rectangular blocks approximately 1 m square in cross section, and roughly 2.6 m in length. Also, there were a variety of markings engraved on the front surfaces; those discovered in this investigation included a cross drawn in the center of a circle, a circle with the character , and a single horizontal line inside a square box. These markings are inferred to indicate the daimyo undertaking the construction, or perhaps the stone mason who did the work, but the precise meanings are unclear.

Similar sites include those on Shōdo island in Kagawa, and at the eastern base of Mt. Rokko in Hyōgo, known as quarries where stone was cut for the walls of Osaka castle of the early modern period, built by the Edo bakufu. (Mikame Yūji)