Ishigaki: The Building Blocks of Life
Dry stone walls (those built without a binding material, such as mortar) are called ishigaki in Japanese. The term is most often applied to the walls and foundations of castles, and indeed, some of the finest examples on Fukue include the walls of Fukue Castle. However, ishigaki walls are found nearly everywhere on the island, ranging from those built of smoothly hewn stonework to those constructed of roughly stacked fieldstones. The abundance of volcanic stone on Fukue has made it an important building material for residents from all walks of life, from domain lords to humble farmers, and its use is central to life in this island environment.
Fukue Castle and the Tomie Stone Storehouse
The surviving walls of nineteenth-century Fukue Castle and the eighteenth-century Tomie Stone Storehouse are perhaps the best-constructed examples of ishigaki on Fukue. The hard basalt has been painstakingly hewn to make the stones fit together evenly, resulting in a smooth outer surface. The effort that went into creating them reflects the structures’ prestige—both were commissioned by lords of the time, who could afford to pay for expert stoneworkers, even bringing them in from other parts of the country. Over the centuries, the wooden roofs, doors, and flooring of the structures have been lost. But despite slow deterioration caused by weather and creeping vines, the stone walls are still standing firm.
Street of the Samurai Quarter
Not far from Fukue Castle is a street of mid-ranking samurai residences that illustrate how Fukue looked as a seventeenth-century castle town. The street stretches about 400 meters and is lined by ishigaki walls that enclose each residence. While the buildings themselves are later reconstructions or renovations, the stone walls are largely original and exhibit a feature found almost nowhere else in the country: the walls are topped with stacks of rounded rocks known as “spilling stones” (kobore ishi). The prevailing theory is that the precariously balanced piles were a form of defense. If an opponent tried to scale the walls in a nighttime sneak attack, the sound of the falling stones would rouse the residents. On each side of a gate, the spilling stones are set between bracketing stones shaped like half circles, another feature of Fukue ishigaki. The bracketing stones are affectionately referred to as kamaboko stones, named for their resemblance to the semicircular slices of fishcake found atop hot soba or udon.
Fields and Farms
Outside of the city of Fukue, ishigaki structures shift from finely hewn basalt to rough, porous lava rock. The change in materials serves as a visual distinction between professionally built structures and rough walls made by farmers from fieldstones. Walls around old farmhouses, windbreaks, tin-roofed sheds, and even lean-tos for drying produce are made from this pitted black stone. On the Miiraku Peninsula, lava rock has been used to construct walls around the distinctive round fields called maruhata. Elsewhere, fields are usually easily plowed squares and rectangles, but in Miiraku, farmers shaped their plots around the gently rounded terraces of the lava plateau and the naturally winding flow of water it creates. Lava-rock walls surround the fields to prevent soil erosion while allowing excess water to escape. Because rice requires standing water to grow, these fields are generally used to grow sweet potatoes, barley, and soy.
Kanjiga Castle
On the southern coast of the Tomie Peninsula, another curious example of ishigaki is found in a place called “Kanjiga Castle” or the “Yamazaki Stone Fort.” The ruins of a maze-like seaside fort peek out from the greenery, with roughly formed basalt walls stretching some 180 meters. The exact origins of the fort are a mystery, as there are no records of its construction. However, several features suggest it was once a pirate hideout. First, it is situated in a secluded location, protected by reefs, but with access to the open sea. Next, the fort was constructed with only one entrance, and the walls were dotted with peepholes. Ming dynasty coins, pottery fragments, and human remains unearthed at the site support this idea. Another theory, this one from local folklore, is that the structure was built by a carpenter named Kanji with the assistance of a kappa: a supernatural, turtle-like creature that commonly appears in Japanese folktales.