門柱の石組みは様々な石質と大きさや形を組み合わせています。「黒」が硬石で、他は「軟石（凝灰岩）」です。普通は一種類の石質と大きさを揃えています。
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Gatepost
The stonework of the gateposts combines various the quality of the stone with their size and shape. The black color stone is hard stone, others are soft stone(tuff). Usually one type of stone and the same size.