Ohori Park was the largest park I saw in Japan, and contained the most beautiful traditional Japanese garden I saw (we travelled in Tokyo, Kyoto, Osaka, and Kumamoto besides Fukuoka). The park is steps from the subway, and very large. You can walk around the pond or on a bridge/path through the center of it. Entrance to the park is free, and I suggest purchasing a box lunch at the conbini (convenience store) across the street and enjoying it in the park. There are benches at intervals around the pond and around the park.
There is a water fountain in the childrens' playground. I mention this becuase there are not many water fountains in Japan (although there are many vending machines that will sell you a drink for 100-150 yen).
There are bathrooms in the park but they are not the cleanest, and I think there were only Japanese toilets (squat-type).
There is a charge to enter the Japanese garden, but it is well worth it. The large and compact garden (I know that sounds impossible but every step in this garden reveals a new aspect and a new view) has water, flowers, a rock garden, and several paths and bridges connecting them. It is lovely and highly recommended. It is not a huge garden, but I spent more time there than I thought I would because it was so beautiful.
There is also the Fukuoka art museum in the park, which also has an entry fee. The museum is small but nicely laid out, although most rooms do not have a seat or bench (and after walking so much in the park I would have loved to be able to sit looking at the artwork rather than stand). It has a nice mix of modern art pieces, including works by Miro, Dali, Warhol, and Rothko.
The garden was the highlight of the park, in my opinion, but the park is a nice place to spend some time.
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