Yamakawa Sanso, completed in 1977, stands as a remarkable residential design by the renowned architect Riken Yamamoto. Located in the rural landscape of Minami-Maki Village in Nagano Prefecture, this private residence exemplifies Yamamoto's innovative approach to architectural design during the 1970s. The structure demonstrates his characteristic sensitivity to natural surroundings and spatial composition. Built as a mountain retreat, Yamakawa Sanso reflects the architect's philosophy of harmonizing contemporary design principles with the vernacular context of its alpine setting. This work represents an important example of residential architecture from Yamamoto's early career.