The Shin River, 10 kilometers (6.2 mi) in length, flows through Yachiyo and forms the upper part of the Inba Discharge Channel.

[4] A 19 kilometers (12 mi) walking path was built by the city of Yachiyo, and features a pedestrian suspension bridge with an observation platform.

[5] Chiba Prefecture Yachiyo has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

Yachiyo has been inhabited since the Japanese Paleolithic period, and archaeologists have found stone tools dating to over 30,000 years ago.

Yachiyo has a mayor-council form of government with a directly elected mayor and a unicameral city council of 28 members.

In terms of national politics, the city is part of Chiba 2nd district of the lower house of the Diet of Japan.