Eigenzan Park, Municipal park in Shunan City, Japan.

Eigenzan Park is a municipal park in Tomita, Shunan, Yamaguchi Prefecture, laid out in 1970 to mark the cityhood of the former Shin-Nanyo City. It is built around the theme of water and has two zones: a developed urban zone using the slope of Mount Eigenzan and a conservation zone of wooded groves. Near the summit stands the Yume Fusha, a 24 m Dutch-style windmill with 24.66 m sails, completed in 1995; its reinforced-concrete building has seven floors above ground, with exhibition rooms on the first two. The park also holds a pool complex finished in 1990.

Eigenzan Park opened in November 1970 to mark the city status of the former Shin-Nanyo City, now part of Shunan. It was laid out around water, with a developed zone using the terrain of Mount Eigenzan and a conservation zone of wooded slopes. The Green Environment Cooperative manages it as designated administrator, and the park has carried paid naming rights since 2021.

The park's name comes from Eigenzan, the hill it occupies in the Tomita district of Shunan. Each August the Sun Festa Shinnanyo summer festival centres on a large stage at the Shin-Nanyo rotary, and the event closes with fireworks launched from the park, a fixture of the local summer calendar.

The park is a five-minute drive from JR Shin-Nanyo Station, or about fifteen minutes by car from the Tokuyama-Nishi Interchange of the Sanyo Expressway via Route 2. The pool operates from July 21 to August 31, 10:00 to 18:00, with a ten-minute rest at every full hour and a safety check about every twenty minutes; it closes in bad weather.

The Yume-Fusha is a Dutch-style grain mill completed in 1995 near the summit, standing 24 m tall with 24.66 m sails, among Japan's largest. It is lit every night and can be seen from the Route 2 Shunan bypass. Its concrete building has seven floors above ground, with exhibition rooms on the first two.