I actually came this time entirely for Gyokusendo Cave. I originally thought I could leave after seeing the limestone cave and checking out some traditional Okinawan buildings, but once I went in, I realized the layout of Okinawa World is incredibly well designed. There's basically no way to pick and choose only what you want to see.
The route through the park starts with Gyokusendo Cave. After exiting the cave, it naturally leads to the tropical fruit garden, traditional craft experiences, the Ryukyu Kingdom Castle Town, shops, performance areas, and other facilities, one after another. You basically follow the route through the entire park. I thought three hours would be enough, but everything flowed so smoothly that I ended up staying for the performance too. I arrived a little after 1 p.m., and by the time I left, it was almost closing time.
That said, Gyokusendo Cave itself is definitely worth making a special trip for. The cave is about 5 kilometers long, with around 890 meters currently open to visitors, and it contains over one million stalactites. Walking through it is truly spectacular. Along the way, you can see the many different forms created by the stalactites, and even small stalagmites slowly forming where water has been dripping near the walkway for years.
I really liked the lighting inside. It illuminates the cave clearly without giving it that cheap tourist-attraction feel from excessive lighting. Instead, it beautifully brings out the layers and shapes of the different stalactites. There are a few things to keep in mind when visiting, though. The cave has plenty of ups and downs, and the ground can get wet. Some stalactites hang so low over the walkway that protective padding has been installed. Taller visitors really need to watch their heads, because if you hit one, people might be more worried about the stalactite than your head.
Also, Gyokusendo Cave is not wheelchair accessible, and the public route is nearly 900 meters long. If you're traveling with seniors or children, or if you have difficulty with stairs and wet, slippery surfaces, it's best to consider your stamina beforehand.
Overall, the admission isn't exactly cheap, but the scale and scenery of Gyokusendo Cave are impressive. Along with the traditional Ryukyu buildings, craft experiences, tropical plants, and live performances afterward, I still recommend setting aside half a day if it's your first time in Okinawa. The overall atmosphere really doesn't feel like Japan.