The Yokomizo family were the headmen of their village and had a very substantial property, which their heirs donated to Yokohama.
The city has restored the five surviving buildings—the gate (with built-in storerooms, shown here), the handsome main house, a separate building for raising silkworms, a granary, and a document storehouse—and opened them to the public as a park/history museum. The interior is preserved to show what farm life (farm life on the high end of the scale, to be sure) was like in the past.
Thatched-roof buildings such as these are rapidly disappearing from Japan. It’s rather amazing to have such a fine set of them preserved in Yokohama, which is so identified with modernity and where what was countryside a century ago has been so rapidly urbanized.