Located in the southeastern part of Oita Prefecture, Saiki borders Tsukumi City to the north, Usuki City and Bungo-Ono City to the west, and the Miyazaki Prefecture border to the south. From the south to the west, it is surrounded by mountains that form part of the Sobo-Kyoto National Park, and to the east, it faces the Bungo Channel with a view of Shikoku in the distance, and has a beautiful ria coastline that stretches for about 270 km and is designated as the Nippori Coast National Park. The average annual temperature is around 16 degrees, and the climate is warm, with very little snowfall even in winter. It’s also a region blessed with abundant water, with many tributaries, including the Banjo River, one of Kyushu's cleanest rivers, and the city center is located on the alluvial plain that spreads out at the mouth of the Banjo River.
(Source: Saiki City Government Website)