Akita Prefectural Koizumigata Park, Municipal park in Akita, Japan.

Akita Prefectural Koizumigata Park is a recreational area in Akita featuring open green spaces, walking trails, and multiple ponds throughout its grounds. The layout combines open lawns with quiet water features and cultivated gardens that together create a varied landscape for visitors to explore.

The park grew around the man-made ponds Onogata and Megata, whose wetland plant communities were designated a prefectural natural monument in March 1987. The garden Suishin-en opened in April 1979, designed by Tajirō Roku as Akita Prefecture's first circuit-style Japanese garden; it took three years and about one billion yen to complete. In October 1978 the Crown Prince and Princess, later Emperor Akihito and Empress Michiko, planted commemorative trees there with local children.

The park's name comes from the Koizumi district, and its two ponds, Onogata and Menogata, were recorded in the 1790s-1800s Kantō Rokugunki as irrigation sources for fields, with a bridge, Otakano-bashi, between them. The ponds' wetland plant communities were designated an Akita Prefectural Natural Monument in March 1987. The garden Suishin-en takes its name from a poem by Rikinosuke Ishikawa, a wealthy farmer's son from a branch of the Nara family who was born near the ponds.

Visitors will find parking areas, restrooms, and picnic spaces spread across the grounds for convenience. Walking trails are clearly marked, though most directional signs are in Japanese, so reviewing a map beforehand helps with navigation.

The two central ponds, Onogata and Menogata, were designated a prefectural natural monument in March 1987 for their wetland plant communities. The Edo-period text Kansei Rokugunki records a sunken boat in the marsh that locals said became a dragon, after which boating there was avoided in favour of tub-shaped boats.