Bryan I.
Yelp
Really nice garden in the heart of Naha! It's not as big as fancy as some of the world class gardens in Kyoto, but for Okinawa it's quite good!!
It's cheap (200 yen, or less if you have a monorail 1-2 day pass), nice water features & plants, exceptionally exquisite stone sculptures (including 4 huge dragon pillars), and you can feed the fish and turtles for only 100 yen!
If you are nearby, it's definitely worth a visit (it's quite close to kokusai dori, the ferry terminal, bus terminal, and a couple monorail stations).
We spent about an hour slowly walking through but if you're going fast it could take as short as 20-30 minutes.